Free calculator
Daily Calorie Calculator
Estimate maintenance calories using a recognised equation.
Before you use the calculator
What is this calculator for?
A calorie calculator estimates how much energy your body may need each day based on factors such as age, sex, height, weight and activity level. It is designed to give you a practical starting point for understanding energy balance — the relationship between what you eat and drink and what your body uses. The result is an estimate, not a prescription, because real energy needs vary from person to person and from day to day.
What it measures
- Age
- Sex
- Height
- Weight
- Activity level
- Estimated daily energy needs
Why it is here
It can help you understand roughly how much energy you may need to maintain your current weight and, where appropriate, how a modest calorie deficit might support gradual weight loss.
What this result cannot tell you
No calculator can understand everything about you. Important limitations include:
- Metabolic differences
- Changes in activity from day to day
- Medication effects
- Illness and recovery
- Muscle mass
- Accuracy of self-reported activity
- How easy or hard a target feels in real life
The clever bit is not finding the lowest calorie number you can survive on. It is finding an intake you can actually live with while still eating enough protein, fibre and proper food.
How to use the result sensibly
Use the number as a starting point. Look at the overall trend, how you feel, what is happening with your waist, movement, sleep, blood pressure and other relevant health markers. Where the result is unexpected, concerning or difficult to interpret, a qualified healthcare professional can put it into context.
Industry-standard does not mean individually perfect. These calculators use recognised methods because they are useful, not because they can define a person. Results are informational, subjective in context and open to interpretation.
What should I do next?
How this works, limitations & evidence
Interpretation, limitations & evidence
Understand the result — then decide what matters
This calculator estimates the energy needed to maintain your current weight. It uses the Mifflin–St Jeor resting-energy equation and then applies the activity level you select. Your real maintenance intake is the intake that holds average weight broadly stable over time.
How the estimate is calculated
Resting energy ≈ (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5.
The calculator then multiplies resting energy by the selected activity factor to estimate total daily energy expenditure.
Why your real maintenance may differ
Activity is hard to categorise
“Moderately active” can mean very different things to different people.
Body composition differs
Two men of the same weight and height can have different energy expenditure.
Life changes
Work, illness, sleep, training and weight loss itself can change energy needs.
Turning maintenance into a weight-loss target
NHS Better Health commonly uses a reduction of around 600 kcal/day as a general population starting point for weight loss. That is not compulsory and can be too aggressive or too small for some people.
A useful deficit still needs enough food for protein, fibre, micronutrients and a life you can sustain.
How to calibrate the estimate with real life
Use the estimate for 2–4 weeks. Track average weight under reasonably consistent conditions. If weight is stable, your logged average intake is probably close to maintenance. If weight is trending down or up, adjust gradually rather than making a huge change after three days.
Why plateaus happen
As body weight falls, energy needs usually fall. Activity can also drift down without you noticing, and portion sizes can creep up. A plateau does not prove your metabolism has stopped working.
When calorie counting is not the right tool
If tracking creates obsessive behaviour, significant anxiety or worsens an eating disorder, step away from the calculator and seek individual support. You can create structure through portions, meal templates and food quality without counting every calorie forever.
Common questions
Is this my exact calorie requirement?
No. Predictive equations have individual error and activity multipliers add more uncertainty.
Should I eat back exercise calories?
Usually not automatically; wearable and exercise estimates are rough.
How often should I recalculate?
After a meaningful weight change, major activity change or if your real trend no longer matches the estimate.
What should I use next?
Sources & methodology
We use UK guidance and primary research where appropriate, and disclose when a result is an estimate rather than a clinical threshold.
Use this page as information, not judgement. The best next step is the one that actually fits your health, your life and what you are ready to change.
Written and editorially reviewed by the Shift Some Timber. Editorial review is not clinical review. Health content is checked against recognised UK guidance and primary sources where appropriate.
Last reviewed: 8 August 2026. This page is informational and does not replace individual medical advice.