Your maintenance calories are the amount you can eat each day without gaining or losing weight. They are the starting point for any diet, because losing weight means eating below them and gaining means eating above them. There are two ways to find the number. One is to estimate it from your size, age and activity with an equation. The other is to use what your own body shows: if you know what you ate on average and how your weight changed, you can work backwards. This calculator does both. The formula is quick and good enough to start with; the log method turns your tracking into a personal figure.
How to use the maintenance calorie calculator
- Choose a method. Pick the estimate if you have not tracked anything yet, or the log method if you have at least two weeks of food and weight data.
- For the estimate, enter sex, age, height, weight and a realistic activity level.
- For the log, enter your weight at the start and at the end, the number of days and your average daily calories.
- Read the figure and the range, then try eating at that level for a couple of weeks and adjust.
Maintenance calorie formulas
From a log: maintenance = average daily intake − (end weight − start weight) × 7,700 ÷ days
W is weight in kilograms, H height in centimetres and A age. The BMR equation is Mifflin-St Jeor (Am J Clin Nutr 1990;51:241–247). The activity multipliers are the midpoints of the Physical Activity Level categories of the Institute of Medicine’s Dietary Reference Intakes for Energy (2005).
| Activity level (IOM 2005) | PAL range | Multiplier used here |
|---|---|---|
| Sedentary | 1.0 – 1.39 | 1.2 |
| Low active | 1.4 – 1.59 | 1.5 |
| Active | 1.6 – 1.89 | 1.75 |
| Very active | 1.9 – 2.5 | 2.2 |
The log method rests on the energy balance principle: a change in stored energy equals intake minus expenditure. The conversion of 7,700 kcal per kilogram (3,500 per pound) is from Wishnofsky (Am J Clin Nutr 1958;6:542–546). It is approximate, and Hall et al. (Lancet 2011;378:826–837) discuss why it should not be extended over long periods.
Worked examples
Estimate. A 35-year-old woman, 168 cm, 65 kg, low active.
- BMR = 650 + 1,050 − 175 − 161 = 1,364 kcal
- Maintenance = 1,364 × 1.5 = 2,046 kcal, with a likely range of 1,841 to 2,251.
From a log. Over 28 days someone eats an average of 2,200 kcal and goes from 80 kg to 78 kg.
- Weight change = −2 kg, equal to −2 × 7,700 = −15,400 kcal, or −550 kcal a day.
- Maintenance = 2,200 − (−550) = 2,750 kcal.
How weekly weight change maps to maintenance
If you ate 2,200 kcal a day, your maintenance would be:
| Weight change | Energy balance (surplus +, deficit −) | Maintenance if you ate 2,200 kcal a day |
|---|---|---|
| -1.00 kg per week | -1,100 kcal | 3,300 kcal |
| -0.50 kg per week | -550 kcal | 2,750 kcal |
| -0.25 kg per week | -275 kcal | 2,475 kcal |
| 0.00 kg per week (stable) | 0 kcal | 2,200 kcal |
| +0.25 kg per week | +275 kcal | 1,925 kcal |
| +0.50 kg per week | +550 kcal | 1,650 kcal |
| +1.00 kg per week | +1,100 kcal | 1,100 kcal |
Getting a reliable log
- Track for two to four weeks so day-to-day water swings average out.
- Log everything, including drinks, oils and weekend meals.
- Use weekly average weights rather than single readings.
- Keep activity steady, since a change halfway through muddles the result.
After you find it
To lose weight, eat below maintenance (see the Calorie Deficit Calculator); to gain, eat above it (see the Weight Gain Calculator). The TDEE Calculator breaks total energy down by activity, the Calorie Calculator gives targets, and the BMR Calculator and RMR Calculator focus on resting needs. Very low targets should be set only with medical advice.
This page is for information only and is not medical or dietary advice. Speak to a doctor or registered dietitian about your own needs.
Sources
- Mifflin MD, St Jeor ST, et al. Am J Clin Nutr 1990;51:241–247.
- Institute of Medicine. Dietary Reference Intakes for Energy, 2005.
- Wishnofsky M. Caloric equivalents of gained or lost weight. Am J Clin Nutr 1958;6:542–546.
- Hall KD, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet 2011;378:826–837.
Frequently asked questions
What are maintenance calories?
Maintenance calories are the daily energy intake at which your weight stays steady over time. If you eat that amount on average, intake equals what your body uses for resting needs, digestion, daily movement and exercise.
Which method is more accurate, the formula or the log?
A well-kept log is usually better because it reflects your real body. The formula is an average for people of your size, accurate to about 10 percent. A log needs at least two to three weeks of consistent food tracking and morning weigh-ins to be useful, and short logs are affected by water changes.
Why does the log method use 7,700 kcal per kilogram?
It is the traditional estimate of the energy in a kilogram of body weight change (3,500 kcal per pound), from Wishnofsky (1958). It is approximate: the exact figure depends on whether the change is fat or lean tissue and water. Over several weeks, it gives a reasonable result.
How should I log my weight?
Weigh yourself first thing in the morning after using the toilet, on the same scale, and use averages for the first and last week rather than single days. Record all food and drink for the whole period; unlogged snacks make the result too low.
Does maintenance change over time?
Yes. It falls as you lose weight and rises as you gain, with age, and with changes in activity. Recalculate every few months or after a change of several kilograms.