Calorie Calculator

How this calorie calculator works

Enter your age, your weight, your height, the equation’s sex category and an activity level. The tool estimates your resting energy expenditure, then multiplies it by an activity factor to reach total daily energy expenditure (TDEE), also called maintenance calories. If you want the expenditure side of that arithmetic laid out in full, the TDEE calculator shows every step.

The tool uses the simplified equations from Mifflin and colleagues’ 1990 study. Weight is in kilograms, height in centimetres and age in years:

• Male: 10 × weight + 6.25 × height − 5 × age + 5.
• Female: 10 × weight + 6.25 × height − 5 × age − 161.

The interface calls the resting estimate BMR, which is the label most calculators use. Mifflin’s study predicted resting energy expenditure, measured after a short rest in a lab. A true basal metabolic rate requires an overnight fast and a wake-up measurement before you move. The two figures sit within a few per cent of each other for most adults, and they are not the same quantity.

Choose an activity level

Think about the whole week, including your job, your commute and your training. The multipliers are broad calculator assumptions. Nobody measured your activity, and these factors were never part of Mifflin’s resting-energy equation. A desk job plus three gym sessions lands in the light or moderate band, well short of the top two.

For more context, read the activity-level guide.

Worked example: 70 kg, 175 cm, age 30

Using the male equation: 700 + 1,093.75 − 150 + 5 = 1,648.75 kcal at rest. At an activity factor of 1.55, that becomes 2,555.56 kcal per day. The screen rounds these to 1,649 and 2,556 kcal. You picked the 1.55 yourself from a five-item menu, which makes it the softest number in the sum by a wide margin. Moving one band up, to 1.725, adds about 200 kcal to the daily figure without changing anything you do.

What the calorie results mean

Maintenance is the estimated intake corresponding to TDEE. The lower and higher numbers illustrate TDEE minus 500 and plus 500 kcal. They are worked examples, and nobody has prescribed them for you. A flat 500 kcal cut lands differently on a 1,600 kcal maintenance estimate than on a 3,000 kcal one.

A fixed calorie gap does not produce a fixed rate of weight change, because your energy needs move as your weight and your activity move. For an adult exploring a time-based weight scenario, the NIDDK Body Weight Planner models those changes week by week.

1,200 calories a day for women and 1,500 for men are the floors most clinicians work from without supervision; the 2013 AHA/ACC/TOS obesity guideline gives the ranges as 1,200 to 1,500 and 1,500 to 1,800. Below those figures the plate runs out of room before protein, calcium, iron and the B vitamins are covered. This tool withholds the minus-500 example when it would fall under 1,200 for the female equation or 1,500 for the male one. Clearing that display limit says nothing about whether the target suits you, so take any weight-loss target to a dietitian or your doctor if you want guidance built around your own history.

Why your actual needs may differ

Two layers of uncertainty stack up here. The resting equation carries its own error for any individual, and then you multiply that figure by an activity band you estimated. Your health conditions, your medications, your body composition and any change in how much you move all push the real number around on top. The body fat calculator and BMI calculator describe different aspects of body size; neither one measures metabolism.

Use the tool for general adult education. Children, pregnancy, breastfeeding, eating-disorder recovery and medical nutrition planning all need care this page cannot give. Do not change prescribed nutrition on the strength of its result.

Compare maintenance, deficit and surplus scenarios

Use the adjustment menu to compare maintenance with 10% or 15% less, or 5% or 10% more. Each scenario multiplies your unrounded TDEE by the chosen factor. For the example above, 10% below maintenance is about 2,300 kcal/day; 5% above is about 2,683 kcal/day. The result also converts energy to kilojoules using 1 kcal = 4.184 kJ.

The activity comparison recalculates maintenance for all five multipliers from the same resting estimate. That puts the cost of one assumption on screen: choosing a higher category moves your estimate and leaves what you burn exactly where it was. Use the activity-level guide if you are unsure which band fits your week.

These scenarios compare intakes. They cannot give you a date or a weekly rate of weight change. Deficit scenarios below the tool’s display limit are withheld, and clearing that limit still does not establish a suitable intake for you. For a model that accounts for changes over time, see the NIDDK Body Weight Planner.

Copy or print your calculation

Open How your result is calculated and you get the Mifflin equation with your own age, weight and height substituted in, the activity multiplication, and each scenario worked out from the unrounded TDEE. The steps run the same arithmetic as the headline figures, with intermediate numbers rounded so they read cleanly.

Copy results puts your inputs, the labelled results, the calculation steps and the notes on your clipboard. Print / save PDF opens a report preview and then your browser’s print dialogue, where Save as PDF is usually one of the options. Read the report before you send it to anyone, because it carries the measurements you typed in. Reset example puts the sample values back and leaves your unit choices alone. All of this happens in your browser, and the tool keeps no history of your calculations.

Common questions

Are TDEE and maintenance calories the same?

In this calculator, yes. TDEE estimates total daily energy use; maintenance calories is the intake that would approximately match it.

What is the difference between BMR and TDEE?

The BMR-labelled result estimates resting energy use. TDEE multiplies that result by an activity factor to include a rough allowance for daily movement and other energy expenditure.

Do I add exercise calories to TDEE?

The activity multiplier already includes an exercise allowance. Adding a tracker’s exercise calories on top counts the same session twice.

Will subtracting 500 calories make me lose a pound every week?

No. Your body weight, your water balance, your activity and metabolic adaptation all pull on the outcome. Read the displayed adjustment as a worked example, and expect the real rate to wander.

Can I use pounds and feet?

Yes. Choose your weight and height units. Values are converted to kilograms and centimetres before the calculation.

Written and maintained by Rowan Hale, the site author’s pen name. Updated September 13, 2026. No medical or dietetic qualification is claimed. Read our editorial policy or report a calculation error.