Calorie Deficit Calculator: Safe Daily Calorie Target
Enter your sex, age, height, current weight, goal weight and activity level, and this calorie deficit calculator returns a daily intake with the deficit in kcal. We show weeks at each safe rate, never a finish date.
Why this number
How our calorie deficit calculator sets your target
Five steps, all of them visible. The rails live in the arithmetic, so the number you read has already been checked before it reaches the screen.
You enter what you know
Sex, age, height, current weight, goal weight and activity level. Switch units at any time. If a field is empty or out of range, the message tells you which field and what to change.
We test the goal weight
A goal weight that lands under a BMI of 18.5 is rejected with a plain explanation, not a warning triangle. We will show you the bottom of the healthy range instead and let you pick again.
We estimate your expenditure
Mifflin-St Jeor for BMR, then an activity multiplier for TDEE, printed with a plus or minus 12.5 percent band. That band carries through to your intake target, because the input is an estimate.
Three safety rails run in the maths
Loss is capped at 1 percent of bodyweight per week. Intake never drops below 80 percent of TDEE. Absolute floors are 1,500 kcal for men and 1,200 kcal for women. If a rail bites, we show the capped target and name the rail.
You read weeks, not a date
The result table gives daily intake, weekly deficit and expected weeks to your goal weight at four paces. Later weeks run slower than the table, because TDEE falls as you get lighter.
03
How we work
A clear path from first conversation to finished work.
Body composition calculators
BMI, Asian BMI, body fat, skinfold, relative fat mass, lean body mass, FFMI, ideal and healthy weight range, frame size and recomposition tools, each printing the classification systems side by side with stated error bands.
Fat distribution calculators
Waist circumference, waist to height ratio, waist to hip ratio, body roundness index and a visceral fat tape proxy, mapped to published thresholds and clearly labelled as tape measures rather than scan volumes.
Calorie and nutrition calculators
BMR, TDEE, calorie deficit and surplus, macros, protein, water, fibre, weight-loss time, check-in, reverse diet and alcohol tools, with intake floors, weekly rate caps and no finish-date countdowns.
Fitness calculators
Calories burned, walking and running energy cost from published MET values, heart rate zones, VO2 max field tests and one rep max estimates, shown gross and net where that distinction matters.
We cap loss at 1 percent of bodyweight a week, we never take intake below 80 percent of your TDEE, and we hold hard floors of 1,500 kcal for men and 1,200 kcal for women. If a rail changes your number, we tell you which one and why. We will not print a countdown to a goal date, because nobody can calculate one honestly.
Which tool next
Four tools that answer what a deficit cannot
Your intake target is one input. These carry your figures across so you are not typing height and weight again.
Your energy expenditure
A deficit is only as good as the TDEE under it. Get your BMR from five equations, then the activity multiplier, with the plus or minus 12.5 percent band shown next to the number.
Where your goal weight sits
Before you choose a goal weight, see it against the WHO table and the Asia-Pacific cut-offs side by side. This is also how we test a goal weight against BMI 18.5.
Fat mass versus lean mass
Scale weight moves for reasons that have nothing to do with fat. The US Navy tape method gives a body fat estimate with its honest error band of three to four points against DEXA.
The measure that tracks first
Waist often shifts before the scale does, which is why we ask you to re-measure during a stall. Under 0.5 is the line we hold you to, mapped to published thresholds.
05 — Common questions
What people ask about calorie deficits
Six questions we get most often, answered with the same numbers the calculator uses.
Frequently Asked Questions
- How accurate is a calorie deficit calculator?
- Accurate enough to plan with, not accurate enough to trust to the calorie. The weak link is TDEE, which is an estimate from an equation, so we print a plus or minus 12.5 percent band around it and around your target. On a 2,600 kcal expenditure that is roughly 325 kcal either way. Treat the number as a starting point, hold it for three or four weeks, then adjust from your own weight trend.
- Why will you not show me a goal date?
- Because a date implies precision we do not have. Weight loss is not linear, water shifts can hide fat loss for weeks, and expenditure falls as you get lighter, so a countdown drifts almost immediately. Instead we show expected weeks at 0.25, 0.5, 0.75 and 1 percent of bodyweight per week, after the rails are applied. Weeks let you compare paces honestly. A date only sets you up to feel behind.
- What happens if my goal weight is too low?
- We reject it and say why in plain words. Any goal weight that puts you under a BMI of 18.5 is refused, and we show the bottom of the healthy range for your height so you can pick a new figure. The calculator will not quietly build a plan toward an underweight target. If you are aiming that low for a sport or a weight class, that belongs with a clinician, not a web form.
- Which safety rail changed my target?
- We name it on the result. The three rails are a cap of 1 percent of bodyweight per week, a floor at 80 percent of your TDEE, and absolute floors of 1,500 kcal for men and 1,200 kcal for women. The one that bites first wins. So if you ask for a fast pace at a modest expenditure, you will usually see the 80 percent of TDEE rail applied, with the capped intake shown rather than the number you requested.
- Why plan with 7,700 kcal per kilogram?
- It is the same figure as the familiar 3,500 kcal per pound, converted. A pound is 0.4536 kg, and 3,500 divided by 0.4536 gives about 7,716, which we round to 7,700 kcal per kilogram. Both are planning constants drawn from the energy in stored fat tissue, not measurements of your body. Over long diets they overstate loss, which is one reason our tables cover several paces instead of one confident line.
- Do you store my measurements?
- No. Nothing you type is saved to an account or sent anywhere for storage. Values live in the page and, if you choose to carry them to another tool, in the link itself, so closing the tab is enough to clear them. There is no sign up and no email capture on this site. This page is general information about energy balance, not medical advice, and it is not a substitute for care from your GP or an accredited practising dietitian.
Get the expenditure right, then set the deficit
Run your TDEE, bring the figure back here, and pick a pace you can hold for the next three weeks. Your values travel with the link.