WiseCalcs

Calorie calculator

Enter body details for ages 19–78, select activity and a goal, then follow the visible chain from estimated resting energy through activity factor and estimated maintenance to the fixed goal adjustment.

Written by Kenneth Schrøder, Founder of WiseCalcs

Updated ·Sources verified

See how estimated resting energy, the selected activity factor, estimated maintenance, and a fixed goal adjustment combine into a daily calorie estimate.

kg
cm

Estimated daily calories

2,759 kcal

1. Estimated resting energy (REE)
1,780 kcal
2. Selected activity factor
Moderately active × 1.55
3. Estimated maintenance
2,759 kcal
4. Fixed goal adjustment
Maintain weight: 0 kcal
If activity is Lightly active (1.375)
2,448 kcal
If activity is Very active (1.725)
3,071 kcal

The result shows estimated resting energy → selected activity factor → estimated maintenance → fixed goal adjustment, plus the maintenance estimate at adjacent activity levels. It is limited to ages 19–78 and is not medical or dietetic advice or a prediction of weekly weight change.

How does it work?

Estimated maintenance is resting energy times the selected activity factor. The −500 or +500 kcal amount is a fixed calculator preset, not a prediction of weekly weight change.

Daily calorie formula

cal=REE×activity+goal\text{cal} = \text{REE} \times \text{activity} + \text{goal}
cal
Daily calorie target.
REE
Estimated resting energy expenditure (Mifflin-St Jeor).
activity
Activity factor, 1.2 to 1.9.
goal
Adjustment: 0 maintain, −500 lose, +500 gain.

An 80 kg, 180 cm, 30-year-old man has estimated resting energy of 1780 kcal. At moderate activity (×1.55), estimated maintenance is 2759 kcal; the lose preset gives 2259 kcal.

Expert tips

  • The Mifflin-St Jeor study population was aged 19 to 78, so inputs are limited to that range. This estimate is not designed for pregnancy or breastfeeding or clinical nutrition needs, and it does not replace individual medical or dietetic advice.

Method & sources

Estimated resting energy uses the Mifflin-St Jeor equation. Activity factors run from 1.2 (sedentary) to 1.9 (high activity). The lose and gain choices apply a fixed −500 or +500 kcal calculator preset after estimated maintenance.

Sources

Where this method comes from — use these references to understand the formula, assumptions, and limits.

How we calculate

  • Estimated resting energy uses the Mifflin-St Jeor equation.
  • Activity factors run from 1.2 (sedentary) to 1.9 (high activity).
  • The lose and gain choices apply a fixed −500 or +500 kcal calculator preset after estimated maintenance.
  • The preset is not a prediction of weekly weight change; the calculator does not model metabolic adaptation over time.

Limitations

  • The Mifflin-St Jeor study population was aged 19 to 78, so inputs are limited to that range. This estimate is not designed for pregnancy or breastfeeding or clinical nutrition needs, and it does not replace individual medical or dietetic advice.

Rounding

Calories are shown as whole numbers. The calculation uses full precision.

What this calculator does

The calculator estimates adult resting energy with the Mifflin-St Jeor equation, multiplies it by the selected preset activity factor for maintenance, then applies 0, −500, or +500 kcal for the chosen goal. Every step and the selected factor remain visible in the result.

How to use it

  1. Enter your weight, height, age, and sex.
  2. Pick the activity level that matches your week.
  3. Choose a goal: maintain, lose, or gain.
  4. Read the full resting energy → factor → maintenance → fixed adjustment chain and compare the adjacent activity levels.

A worked example

For an 80 kg, 180 cm, 30-year-old man, estimated resting energy is 1780 kcal. Moderate activity selects 1.55, giving 1780 × 1.55 = 2759 kcal estimated maintenance. The fixed lose adjustment subtracts 500 kcal, so the displayed target is 2259 kcal; it is not a weekly weight-loss promise.

Choosing an activity level

Activity selection is an assumption, not a measurement. The result therefore shows the selected factor and the maintenance estimate for the immediately lower and higher preset levels. DGE also describes total energy as resting energy multiplied by PAL, but WiseCalcs' five preset factors are its own simplified choices and not a direct implementation of DGE's PAL table.

Common mistakes

  • Overestimating activity, which inflates the target.
  • Treating the fixed ±500 kcal preset as a guaranteed weekly weight change.
  • Using the estimate for a child, pregnancy or breastfeeding, or clinical nutrition without professional guidance.

When it's useful

Setting a calorie goal for a diet, planning for weight change, or checking whether your current intake matches your activity.

FAQ

How are daily calories calculated?
Estimated resting energy from the Mifflin-St Jeor equation is multiplied by an activity factor for maintenance, then a fixed goal adjustment of ±500 kcal is applied.
Does the −500 kcal preset predict weekly weight loss?
No. It is a fixed calculator preset applied after estimated maintenance. Body weight changes dynamically, and this calculator does not model metabolic adaptation, appetite, or changes in energy expenditure over time.
Why is maintenance higher than resting energy?
Estimated resting energy covers rest. Maintenance applies the selected activity factor to estimate energy for daily activity and exercise.
How accurate is the estimate?
It's a solid starting point, but metabolism varies. Track results over a few weeks and adjust the target as needed.
Should I eat back exercise calories?
The activity factor already includes typical exercise, so adding more on top risks double-counting. Adjust by results instead.
Can I share a calculation?
Yes. Use Share to copy a link that reopens the calculator with the same details.

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