Calorie calculator — daily calories to lose, keep or gain weight
Set a goal weight and a weekly rate, and get your daily calorie target plus a week-by-week timeline showing when you would reach it.
- Runs in your browser
- Nothing you enter is sent
- Free, no account
These equations were built from male and female reference groups — pick the one closest to your physiology.
5 ft 5.4 in
163.1 lb · 11 st 9.1 lb
143.3 lb · 10 st 3.3 lb
Steady — 0.5 kg/week, about 0.68% of your body weight per week.
Calorie targets are estimates built on population averages. If you are pregnant, breastfeeding, under 18, or managing a condition like diabetes or an eating disorder, set targets with a clinician rather than a calculator.
At 1,453 kcal a day you should reach 65 kg in about 21 weeks.
| Week | Date | Weight | Change so far |
|---|---|---|---|
| 0 | — | 74 kg | — |
| 4 | — | 72 kg | −2 kg |
| 8 | — | 70.2 kg | −3.8 kg |
| 12 | — | 68.4 kg | −5.6 kg |
| 16 | — | 66.7 kg | −7.3 kg |
| 20 | — | 65.1 kg | −8.9 kg |
| 21 | — | 64.7 kg | −9.3 kg |
The formula, with your numbers
- BMR (Mifflin-St Jeor)
- (10 × 74) + (6.25 × 166) − (5 × 32) − 161 = 1457 kcal
- Maintenance
- 1457 × 1.375 = 2003 kcal/day
- Daily adjustment
- 0.5 kg/week × 7,700 kcal ÷ 7 days = 550 kcal/day
- Target
- 2003 − 550 = 1453 kcal/day
One kilogram of body fat stores about 7,700 kcal (3,500 kcal per pound). The timeline above re-runs the maintenance calculation at each new weight instead of assuming a straight line.
What this means
Eating 1,453 kcal a day puts you in a 550 kcal daily deficit. That is 0.5 kg/week, or about 0.68 percent of your body weight each week.
Weight moves on a weekly average, not day to day. A single salty meal, a hard leg session or a missed bathroom visit can swing the scale by a kilogram of water. Weigh yourself at the same time each morning and only compare seven-day averages.
Recalculate whenever you have lost or gained about 5 percent of your body weight — by then your maintenance has genuinely moved and the old target is no longer the same deficit.
How to use the calorie calculator
- Enter sex, height, current weight, goal weight and age.
- Pick the activity level that matches your real week — read the descriptions, not the labels.
- Choose how fast you want to move. The rate options are per week; slower is nearly always better.
- Read your daily target, then check the projected timeline underneath to see when you would reach your goal weight.
Everything recalculates as you type, and nothing is sent anywhere — the whole model runs in this browser tab.
How the daily target is worked out
There are three steps, all shown with your own numbers in the results panel.
- BMR from the Mifflin-St Jeor equation — the calories you burn at complete rest.
- Maintenance (TDEE) = BMR × your activity multiplier. This is what you would eat to stay exactly the same weight.
- Target = maintenance minus (or plus) the daily energy your chosen rate implies. A kilogram of body fat stores about 7,700 kcal, so losing 0.5 kg a week needs a deficit of 0.5 × 7,700 ÷ 7 ≈ 550 kcal a day.
Why the timeline is a curve, not a line
Most calorie calculators divide the total weight to lose by a fixed weekly rate and print a date. That is wrong, and it is why so many people feel they have "stalled" at week ten when they have not.
As you get lighter, your maintenance falls: there is less tissue to keep warm and less mass to move around. If your intake stays fixed, the deficit shrinks every week, and weight loss slows towards an asymptote. This calculator models that explicitly — it recomputes your BMR and maintenance at each new weight and re-derives the following week's loss. If your intake would never reach the goal, it says so rather than printing a fantasy date.
Choosing a rate
| Rate | Daily deficit | Suits |
|---|---|---|
| 0.25 kg / 0.5 lb per week | about 275 kcal | Lean people, anyone training hard, the last few kilos |
| 0.5 kg / 1 lb per week | about 550 kcal | The default for most people — visible progress, liveable |
| 0.75 kg / 1.5 lb per week | about 825 kcal | Higher starting body fat, short focused phases |
| 1 kg / 2 lb per week | about 1,100 kcal | Only with a lot to lose, and rarely for more than a couple of months |
A useful rule of thumb: aim for 0.5 to 1 percent of body weight per week. At 100 kg that is 0.5 to 1 kg; at 60 kg it is 300 to 600 g. Faster than 1 percent and an increasing share of the loss comes from muscle rather than fat.
Minimum sensible intakes
Below roughly 1,500 kcal for men and 1,200 kcal for women it becomes genuinely difficult to hit protein and micronutrient targets, and adherence collapses. If your chosen rate would push you under that, the calculator holds the target at the floor and tells you. The better fix is to widen the gap from the other side — more walking, more NEAT, more training — rather than eating less.
Very low calorie diets below 800 kcal exist as a medical intervention, but they are supervised for a reason and are outside what any calculator should recommend.
Why the scale lies day to day
Body weight swings by 1 to 2 kg within a single day for reasons unrelated to fat. Glycogen binds about 3 g of water per gram stored, so a high-carb day adds water weight. Sodium, hard training, menstrual cycle phase, travel, and simply not having been to the bathroom all move the number.
Weigh yourself at the same time every morning and compare seven-day averages against each other. A weekly average that has not moved in two to three weeks is a real plateau. A single heavy morning is not.
What to do when progress stops
- Recalculate. If you have lost 5 percent of your body weight, your maintenance has genuinely dropped. Enter your new weight above.
- Re-measure your intake. Portion creep is nearly universal after a few weeks. Weigh food for a week and compare.
- Add movement rather than subtracting food. Another 2,000 steps a day is roughly 80 to 100 kcal and does not make you hungrier the way a smaller dinner does.
- Take a maintenance break. Two weeks at maintenance after a long deficit restores leptin, training quality and sanity, and makes the next block work better.
Questions
How big should a calorie deficit be?
A deficit of about 0.5 to 1 percent of body weight per week suits most people — roughly 0.4 to 0.8 kg (1 to 1.75 lb) for an 80 kg adult. Faster loss costs more lean mass and is much harder to sustain.
Where does the 7,700 kcal per kilogram figure come from?
It is the approximate energy stored in a kilogram of adipose tissue (3,500 kcal per pound). It works well for short horizons, but real loss slows down over time because a lighter body burns fewer calories, which is why the timeline here recalculates each week.
Why did my weight loss stall?
Usually one of three things: your maintenance dropped as you got lighter, portion creep has closed the deficit, or you are holding water after a hard session or a salty meal. Recalculate with your current weight and compare weekly averages, not daily readings.
Is there a minimum I should not go below?
Intakes below roughly 1,500 kcal for men and 1,200 kcal for women make it hard to get enough protein and micronutrients. The calculator flags it when your target lands there and suggests a slower rate instead.