Calculate∑ What your result means
Total Daily Energy Expenditure (TDEE) estimates the calories your body uses in a day including activity, and a consistent deficit below TDEE is the basis for gradual, sustainable weight loss.
Calorie Deficit & TDEE Calculator
Estimate your maintenance calories and a daily target for your chosen calorie deficit.
Your details
kg
cm
years
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kcal/day
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Verified for 2026-27Methodology 2026-27.1 · reviewed 2026-08-08 · review by 2027-03-01
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Change weight to see the effect on your result.
Understand your result
Clear context for the values above.
Weight
Weight is included so you can interpret this estimate and make a better-informed comparison.
Height
Height is included so you can interpret this estimate and make a better-informed comparison.
Age
Age is included so you can interpret this estimate and make a better-informed comparison.
Sex
Sex is included so you can interpret this estimate and make a better-informed comparison.
How to use this calculator
- 1Enter your current weight, height, age, sex, activity level, activity multiplier (auto-filled from activity level, editable), daily calorie deficit target.
- 2Review the headline daily calorie target and the supporting figures beside it.
- 3Change one input at a time to see which assumption has the biggest effect.
- 4Confirm current UK rates and thresholds with an official source before acting.
Explore this calculator
What your result means →The headline daily calorie target is based on the inputs currently shown above.Key terms explained →Review the assumptions, applicable rules, timing and real-world fees before making a decision.How to use this calculator →Enter your figures, review the live result, compare scenarios, then save or print your estimate.The calculation formula →The calculation follows the standard relationship between the displayed inputs. Results update whenever an input changes.Worked example →Using the current values produces 2182 kcal/day.Assumptions and limitations →Review the assumptions, applicable rules, timing and real-world fees before making a decision.Costs or factors not included →Review the assumptions, applicable rules, timing and real-world fees before making a decision.Frequently asked questions →How accurate is this estimate? What should I check before relying on it? Can I save or share the result?
▦ How this calculator works
Resting metabolic rate uses the Mifflin-St Jeor equation, multiplied by an activity factor (1.2 sedentary to 1.9 very active) to estimate TDEE. Your daily target subtracts the chosen deficit from TDEE, and the weekly weight change estimate divides the weekly deficit by roughly 7,700 kcal per kilogram of body fat.
◇ Assumptions and what's not included
This is a population-average formula — actual metabolism varies by individual, and very large deficits (more than roughly 1,000 kcal/day) are generally not recommended without medical supervision.
▤ What to do next
Start with a moderate deficit (around 500 kcal/day, roughly 0.5kg/week), track your actual weight trend over 2–3 weeks, and adjust the target based on real results rather than the formula alone.
UK-specific contextFigures use GBP and current published rates and thresholds.
Reviewed for clarityUpdated 3 August 2026.
ImportantFor planning and educational use — not tax, legal or financial advice.
Your privacy mattersInputs stay in your browser.
Frequently asked questions
Is 7,700 kcal really equal to 1kg of fat?+
It's a widely used approximation — actual energy density of body fat varies slightly, and initial weight changes often include water weight rather than pure fat loss.
Is a bigger deficit always faster and better?+
No, very large deficits are harder to sustain, can increase muscle loss, and are generally not recommended without medical guidance — a moderate, sustainable deficit tends to work better long-term.
Should I recalculate as I lose weight?+
Yes, TDEE decreases as body weight decreases, so recalculating periodically keeps the target accurate as you progress.
Does this account for exercise calories separately?+
No, exercise is folded into the activity-level multiplier rather than added on top — pick the activity level that best reflects your typical week.
Official references
Rules and thresholds used by this calculator are labelled for 2026–27 or formula-labelled period. Review the primary guidance before making a filing, borrowing, benefit or investment decision.
Last source review: 3 August 2026. Calculator results are estimates and may exclude circumstances described in the methodology.