Ideal Body Weight Calculator

Ideal Body Weight Calculator

Use our calcount Ideal Body Weight (IBW) Calculator to compute the “perfect” weight for your height and gender. Simply select female or male, then use the slider or type your height in cm to see your ideal body weight in kg. If interested, read on further to learn how and why this calculator works!

The Ideal Body Weight

Somewhere, there exists an ideal person, and that perfect human has the ideal body weight. Their height and weight are in sublime harmony. Perhaps, that person only exists in the philosophy of Plato’s World of Forms but that has not stopped scientists from coming up with formulas to calculate everyone’s ideal weight.

Not So Ideal

Before delving deeper into the whys and wherefores of calculating ideal body weight (IBW), it must be understood that there is no universally agreed optimum weight for a given height. Leaving aside the philosophical and ethical challenges of human body weight classifications, several practical issues make IBW calculations hard to do.

The main issue is that people are different by nature, so an ideal weight for one person may not be a good weight for another person. A muscle-bound athlete is likely to have a body weight which exceeds the calculated ideal, simply due to the extra muscle tissue. Elderly people suffering from advanced sarcopenia (age-related muscle loss) might have an ideal weight yet be carrying unhealthy fat deposits. Tall and short people are left out from formulas which work best for the average-height person. Likewise for pregnant, large, or small framed people.

Not for Kids

The ideal body weight calculator does not apply to kids, because most (all?) formulae just don’t work with growing bodies. Children’s body proportions change with growth, so weight to height ratios that statistically work well in adult populations make less sense for kids.  Furthermore, popular IBW formulae tend to provide unrealistic results in IBW calculations for people under 152cm in height.

Ideal Body Weight Definition

Caveats aside, it is useful to calculate and aspire to a defined ideal body weight. Why? Because the definition of ideal body weight (IBW) is: the optimal weight associated with maximum life expectancy for a given height, according to Yuan and Sinha. The data to support the concept of IBW comes from life-insurance statistics. Now, who does not want to achieve the weight which gives them the best chance of growing really old?

IBW is a Target

Ideal Body Weight Calculation Formula

There are literally hundreds of different formulae and variations on the most popular formula to calculate the ideal body weight. Before the introduction of BMI, ideal body weight (IBW) formulas were widely used as the yardstick of healthy weight. The IBW formula published in 1974 by Ben Devine is the one most used today. It was first used to estimate how fast drugs passed through obese people compared to others.

Our calcount IBW calculator uses this Devine formula. Whilst not perfect (none of the formulae are), the Devine formula is the most useful one. There may be better, more scientific, IBW formulae out there, but none are more popular than Devine. The actual formula is simple:

For Males: 50 kg + 0.9 kg × (person’s height (cm) − 152)

For Females: 45.5 kg + 0.9 kg × (person’s height (cm) − 152)

The Ideal Body Weight Chart

The Devine formula, plotted on a graph, makes a useful ideal body weight chart. Results above the line are considered to be overweight, whilst those under the line are underweight. The ideal weight for a given height is right on the line.

Ideal Body Weight Chart

What’s the Point?

At the end of the day, there is no such thing as an Ideal Body Weight for an individual person. However, the calculated IBW is a useful number to aim for when purposefully managing body weight to support good health. People who are close to their IBW feel and look better. They generally have better health than people who are nowhere close to their IBW. BMI, WHR and other measures may be better, but only IBW gives you a single, unequivocal targeted ideal weight.

Waist to Hip Ratio

Waist to Hip Ratio: Your Ideal Number

Your waist to hip ratio (WHR) could be a better indicator of healthy body weight than body mass index (BMI). Find you current and ideal waist to hip ratio with this handy calcount WHR Calculator, then read on to learn more about this valuable health metric.

Simply enter the circumference measurements of your waist and hips in centimeters (cm) to calculate your waist-to-hip ratio.

Waist to Hip Ratio

Waist to to hip ratio is a measure of how much fat there is in the middle of your body, an area covering the waist, buttocks, and hips. It is an important measure because an increasing body of research supports the view that fatty mid-sections are particularly bad for health. Multiple studies find that people with central obesity (fat middle sections) suffer health risks even when they have normal BMIs. This is because fat which attaches to internal organs in the midriff is sensitive to hormones such as cortisol (a stress hormone). The fat disrupts healthy endocrine system function to increase the risk of type 2 diabetes and heart disease.

Calculate Waist to Hip Ratio (Formula)

To calculate waist to hip ratio, you need just two measurements: circumference of the waist (W), and the circumference of the hips (H). Divide W by H to get the ratio (R). Thus,

W / H = WHR

This calculation shows why it is not correct to use the phrase Waist To Hip Ratio interchangeably with the phrase Hip To Waist Ratio. The concept is to compare waist to hip, not hip to waist.

WHR Formula

Concept of Waist to Hip Comparison

Why compare the size of your waist to the size of your hips? Is it in any way more informative than comparing height to weight (BMI), or waist to chest (WCR), or wrist to shoulders? According to health scientists, the waist to hips comparison is especially useful for measuring abdominal visceral fat. This is the fat which grows around the vital organs in the space between the chest cavity and the hip bones. A person who grows belly fat a rate faster than hip fat is at a higher risk of weight-related disease. WHR is basically a measure of “belly fat”, so can be more accurate at diagnosing harmful obesity than other measures.

Normal WHR

Normal, or healthy waist-to-hip ratio is an indication that there is not a lot of fat clinging to vital internal organs in the abdominal section. The World health Organisation (WHO) defines normal WHR as being in the range of 0.85 to 0.90 or less, but the definitions are different for men and women.

Ideal Waist to Hip Ratio for Males

The ideal waist to hip ratio for men is 0.95 or lower. This means that your waist should be smaller than your hips by at least 5%. A ratio of between 0.96 and 1 is considered borderline unhealthy, with an increased risk of weight-related health problems. A WHR of 1 and up is unhealthy, because a middle which is larger than the hips is likely to be carrying a high load of abdominal fat. The ideal waist size for men is 102cm or less.

Ideal Waist Size for Females

Women have an ideal waist to hip ratio of 0.80 or lower. This ideal WHR is much lower than it is for men, because women have proportionally larger hips in nature. Women with waist to hip ratios between 0.81 to 0.85 are at moderate risk of weight-related health problems. A WHR of 0.86 and above is considered unhealthy, with a high risk of adverse health effects. The actual ideal waist size for women depends on the size of their hips – it is all about proportion. That said, a general rule of thumb for women is to have a waist measurement of less than 89cm.

Ideal Waist to Hips Ratio Men Women

Beauty and WHR

Waist to hip ratio is a major determinant of generally perceived attractiveness, especially for women. Whilst the waist to chest ratio (WCR) is more important for men, the waist to hip ratio (WHR) is regarded as the single most important factor in body attractiveness for women, according to several scientific studies. A typical study asks large, diverse groups of people to rate a series of digitally altered photographs of models with different WHRs. The results indicate that the “perfect” waist to hips ratio for women is 0.7, and 0.8 for men.

Measure Hips and Waist

It is easy to take a measurement of you hips and waist in the comfort of your home. Standing with back straight and heels on the ground, use a flexible tape to measure around your belly, just above the navel. That is your waist measurement. For the hips, wind the tape around the broadest section of your buttocks to get your hip measurement.

Why use Waist to Hip Ratio?

Although it is a useful health indicator for everyone, waist to hip ratio is especially important for older people. According to the American Journal of Clinical Nutrition, WHR is better at predicting premature death in the elderly than BMI (body mass index). This is probably because BMI, as we note here, does not take the body’s proportion of muscle mass into account. Elder people tend to lose muscle mass through age-related sarcopenia, so the proportion of fat to muscle changes in fat’s favour. An old person can balance muscle loss with fat gain, becoming unhealthier even whilst maintaining a supposedly healthy weight. WHR picks up on this trend as the waist grows in proportion to the hips.

Older people and waist to hips ratio

When is WHR not useful?

Waist to hip ratio is not always a better choice than BMI or simple waist measurements. The main problem is that hip measurements can be subjective and misleading. People who exercise their hips, for example by cycling, tend to grow significant muscle mass around the buttocks/glutes and upper thighs. This muscle mass contributes to the hip measurement to skew the WHR, “hiding” the true amount of abdominal fat. The same problem applies to people with large core muscles around the front abdominal area (abs) and the bottom of the back (lats) which can throw out the waist measurement. To further complicate matters, some people have proportionally wide hips or stout girth due to bone structure, obviating the “normal” waist to hips ratio.


It is easy to measure waist to hip ratio, and it can be a more useful indicator of a healthy body weight than BMI. However, WHR can be misleading in some situations, so it should be used in conjunction with simple waist measurement, fat percentage, body mass index, and other metrics to get a balanced indication of healthy weight.

Calculate your BMI right now!
Dates VS Prunes

Dates VS Prunes (with infographic)

Dates VS Prunes: both popular dried fruit, sweet, and they sort of look the same, but which has more calories? Are they even nutritionally similar? Let’s look at these sweet nuggets in comparison, so that we can find out what is better for you, prunes, or dates?

Differences between Prunes and Dates

In many ways, dates and prunes are interchangeable. They are about the same size, colour, and shape. They’re both sticky and sweet. You can safely substitute one for the other in just about any recipe. Leaving taste preferences aside, which one wins the food choices battle?

Prunes are Plums

Prunes are plums, dried. This comes as a surprise to kids who cannot conceptually equate Nanna’s small wrinkled “medicine” to the juicy purple plum in their lunchbox. The most common prune is the dried Agen plum, today mostly grown in California, USA. It is a so-called “loose stone” plum, which means that the seed easily detaches from the flesh.

Dates are Dates

Dates are dried dates, except for when they are fresh dates. Unlike prunes, dates do not change names and they are not usually known as “dried dates”. Perhaps this lack of distinction is because fresh dates are rarely found in the supermarket.

Are Dates as good as Prunes for Constipation?

Modern studies have backed up the old folk-belief that prunes are an effective home remedy for constipation. In fact, studies like this one show that prunes outperform other high fibre foods like psyllium to keep constipation-sufferers regular. Whilst both dates and prunes have similar amounts of plant fibre, prunes have about ten times the amount of sorbitol found in dates. Sorbitol causes water to enter the colon (large intestine), thus hydrating drier waste and aiding its passage. Dates do help with constipation, but they are not as useful as prunes.

How many Prunes or Dates to eat per day?

It is not a good idea to eat significant quantities of the same fruit, especially dried fruit, every day. Prunes and dates are high-calorie foods which contain relatively large quantities of specific vitamins and minerals which may have undesirable effects when eaten in large quantities. As you may have read in our post on carrots, sometimes usually beneficial vitamins can have a toxic effect if eaten to excess. Instead of eating them daily, have a handful of prunes or dates (about 100g) once or twice per week as part of a balanced diet.

Iron in Dates and Prunes

20% of women and 3% of men are reportedly deficient in iron, so iron is a rightly sought-after food nutrient. Surprisingly, dates and prunes seem to have built up a recent reputation for being iron-rich.  The disappointing fact is that both dates and prunes are comparative lightweights when it comes to iron content. Neither fruit, even in dried form, contains more than one milligram of iron per 100g. This compares poorly to other dried fruit like apricots and tomatoes which can contain ten times as much iron. Even fresh high-iron foods like beans, spinach, read meat, and shellfish, contain 3 to 8 times the amount of iron as prunes and dried dates.

Dates versus Prunes Fibre

Prunes and dates are both high-fibre foods with about 10% of their edible portion being composed of dietary fibre. On a head-to-head basis, dates contain about 20% more dietary fibre than prunes (10g versus 8g per 100g). Whilst this seems like a significant difference, on a practical level it is basically meaningless because of the main reason for the difference: dehydration. As fruit dries, the non-water parts become more concentrated, by weight. Therefore, a relatively drier prune is likely to have more fibre (weight for weight) than a relatively less dry date, even though prunes have a lower nominal fibre content than dates. How “dry” is the prune/date that you eat on a specific date? From a practical perspective, it is effective to think of both dates and prunes as being equally fibre rich.  

Dates VS Prunes for Weight Loss

Which is better for weight loss, dates, or prunes? Dates contain significantly more calories than prunes, but before you reach a quick conclusion stop to consider your other options. Dried fruit like prunes and dates are deceptively high in calories because they pack their nutrition into tightly wrapped packages. A prune has the same nutrition of the plum it was made from because it is the plum it was made from! Think about it: would the average person choose to eat ten fresh plums as an afternoon snack whilst trying to lose weight? Probably not. But that same person might not think twice before downing ten prunes with their 3.30 cuppa. Both dates and prunes are low-volume, high-calorie food options so neither is good for weight loss.


Prunes compared to Dates Nutrition
Comparison of Prunes and Dates Nutrition

Prunes VS Dates Nutrition

On a weight-for-weight basis, dates contain about 45% more calories than prunes (289 calories compared to 200 calories per 100g). With 66 grams per 100g, dates have more than twice as much sugar as prunes, which have 31 grams of sugar per 100 grams of fruit. Dates (14mg/100g) also have twice the sodium of prunes(7mg/100g). Prunes and dates both have 2 grams of protein per 100g. As noted a few paragraphs above, dates have more dietary fibre than prunes, (10g compared to 8g) per 100g. When it comes to micronutrients, dates have the edge over prunes in pretty much everything except Vitamin K and Vitamin A. Dates excel over prunes in two micronutrients: folate (folic acid) and selenium.

Finally, What’s better, Dates or Prunes?

Prunes are better than dates, in our opinion. Prunes have significantly fewer calories than dates. The calories in dates primarily come from fast-burn sugars which can influence the body negatively. Unless a person has a distinct need to supplement their folate levels (e.g. pregnancy), prunes provide similar micronutrients to dates. Prunes contain useful substances like sorbitol and phenols which, together with dietary fibre, help to combat constipation.

That said, both dates and prunes are healthy, nutritious, naturally sweet treats which should be enjoyed in moderation.

How many calories should I Eat by Age

Eat this many Calories a Day by Age

Use this handy calcount Calories by Age tool to calculate how many calories a day you should eat, depending on your current age. Age matters when it comes to the rate of calorie burn, because our metabolism slows as we grow older (and wiser).

When we say, “eat this many calories”, we do so on the assumption that you want to maintain your current weight. To lose weight, eat fewer calories. To gain weight, eat more calories.

Many factors determine how many calories a person needs to eat each day, such as the person’s current weight, exercise level, gender and of course, age. Of these main factors, age is the one that will change, no matter what else happens to the person.

Ageing bodies Slow Down

Age is an important factor when it comes to calorie burn, for the simple reason that it affects the speed at which your body uses the calories you eat. This rate of energy use can be thought of as the “metabolism”. More specifically, the key change with age is a reduction in the Basal Metabolic Rate (BMR).

Even though the body is constantly repairing itself, things just do not get fixed “good-as-new”. There is a gradual build-up of cellular detritus and harmful substances at the smallest scales which negatively affect essential functions. Things like telomeres get shorter. Processes just fall apart in the end. This gradual and general degradation leads to a measurable decline in the speed at which the body extracts energy from food.

For a more detailed explanation of the metabolism and the other factors which affect it, read our Calorie Counter page.

Lifestyle Changes

In addition to the slowing BMR, advancing age is often associated with a general slowdown in activity levels as lifestyles change. It is not unreasonable to assume that a 21-year-old is likely to have a more energetic day-plan than a 56-year-old! Reduced activity means that less energy is needed throughout the day, leading to a feedback loop which facilitates a reduction in muscle-mass and metabolism.

If you are “getting-on” in years, you can break the loop, defy the trend, and prolong your faster metabolism rate by exercising regularly. If possible, do activities that make your muscles work hard.

Increased muscle mass is the surest way to keep your BMR humming as you age. Exercising will not stop you from ageing, but it will keep you healthier for longer!

Calories a Day by Age Table

To get a credible answer for the question “How many calories a day should I eat by age?”, we can apply average heights and healthy weights to generally accepted Estimated Energy Requirements (EER) equations. Thus, this tool will work very well for people who are of average height, healthy weight, and do not do any exercise other than normal day-to-day activities. If you do more exercise than a sedentary person, you can use this table to estimate your required calories by age:

AgeMen, Moderate
Men, High Level ExerciseWomen, Moderate
Women, High Level Exercise
76 and up2,2002,4001,8002,000

This is a simple tool, primarily designed to shed some light on what effect aging has on daily calorie intake requirements. If you want a more detailed calculator which factors in your exact height and weight as well as your age and gender, head on over to the calcount Calorie Calculator. To dig even deeper and find out what your recommended macronutrient intake is (and much more), explore our Calorie Tracker.