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Calorie Calculator

Estimate daily maintenance calories using the Mifflin–St Jeor equation and an activity multiplier. This is an estimate for adults, not an individual nutrition prescription.

Detailed optionsStep-by-step guideWorked examples
Make it yours

Imperial values are converted internally using 1 lb = 0.45359237 kg and 1 inch = 2.54 cm.

Selects the constant in the published Mifflin–St Jeor equation. It does not summarize every individual factor.

years

This adult model supports whole ages from 20 to 100. Children and teens need age-specific assessments.

kg

Use a recent weight measurement in the selected units.

cm

Enter standing height. For imperial units, enter total inches: 5 feet 9 inches = 69 inches.

A rough multiplier for total daily energy use. Frequency labels are approximations; exercise duration and occupation also matter.

Advanced options2 more ways to explore

This optional percentage scenario is educational, not a personal intake recommendation.

%

Subtracts or adds this percentage to estimated maintenance. No weight-change timeline is predicted.

Private by design. Calculated in your browser.
Estimated daily maintenanceLIVE RESULT
2,555.56kcal / day
Understand the energy estimate

An adult educational illustration, not a prescribed intake or a weight-change prediction.

Resting energy (kcal/day)1,648.75
Activity multiplier1.55
Maintenance (kcal/day)2,555.56
Scenario total (kcal/week)17,888.94
Adult educational estimate. See the methods and limitations below.
YOUR ANIMATED GUIDE

Follow your numbers, step by step.

These steps use your current inputs. Choose a step or play the walkthrough.

STEP 1 / 4
1,648.75 kcal
1234

Estimate resting energy

Mifflin–St Jeor uses metric weight, height, age and the selected sex constant.

10 × 70 + 6.25 × 175 − 5 × 30 + 5
Explore at your own pace
ONE ASSUMPTION, A DIFFERENT PERSPECTIVE

Compare activity assumptions

Same measurements, different activity factors. Values show estimated maintenance, before optional adjustments.

Activity sensitivity comparison
Activity assumptionMultiplierMaintenance kcal/day
Sedentary1.21979
Lightly active1.3752267
Moderately active1.552556
Very active1.7252844
Extra active1.93133

Change an input above to explore a different scenario.

How to use this calorie calculator

Estimate resting energy and daily maintenance calories, then compare activity assumptions before exploring an optional percentage adjustment. The calculator uses the Mifflin–St Jeor resting-energy equation. It displays both the resting estimate and the activity-adjusted estimate so you can see which part of the model changes. Daily and weekly totals are energy illustrations, not predictions of weight change.

Resting energy and maintenance are different

The resting-energy calculation uses weight, height, age and a sex constant. The maintenance estimate then multiplies resting energy by an activity factor. This distinction matters: resting energy is not automatically the amount you should eat, and the activity factor is a rough assumption rather than a measurement of your individual metabolism.

Choose activity carefully

The activity menu ranges from sedentary to extra active. The exercise-day descriptions are convenient labels, but two people exercising the same number of days can have different activity totals. Work demands, session duration and everyday movement also affect energy use. The comparison table shows all five multipliers without changing your measurements.

Explore an adjustment without turning it into a prescription

Advanced options let you illustrate maintenance minus or plus 0–20%. This is a mathematical scenario. It does not assess nutritional adequacy, medical conditions or a safe personal target, and it does not calculate a promised rate of weight loss or gain. Individual nutrition planning needs a broader assessment.

What the model leaves out

This adult estimate is not designed for children, pregnancy, breastfeeding or medical nutrition management. It does not use body composition, laboratory measurements or a metabolic test. The weekly total simply multiplies the daily scenario by seven; it does not model day-to-day changes or adaptation.

Calorie formulas, explained

Mifflin–St Jeor resting energy

REE = 10 × kg + 6.25 × cm − 5 × age + constant

The selected equation constant is +5 for male and −161 for female.

Estimated maintenance

Daily maintenance = REE × activity factor

The selectable factors are 1.2, 1.375, 1.55, 1.725 and 1.9.

Optional energy illustration

Scenario = maintenance × (1 ± adjustment/100)

Daily scenario × 7 gives the weekly energy total.

EVERY OPTION, EXPLAINED

Know what goes into your result.

Use this reference to check units, assumptions and advanced settings.

Calorie calculator input reference
Input or optionWhat it means
Measurement systemImperial values are converted internally using 1 lb = 0.45359237 kg and 1 inch = 2.54 cm.
Sex constant in the equationSelects the constant in the published Mifflin–St Jeor equation. It does not summarize every individual factor.
Your ageThis adult model supports whole ages from 20 to 100. Children and teens need age-specific assessments.
Your weightUse a recent weight measurement in the selected units.
Your heightEnter standing height. For imperial units, enter total inches: 5 feet 9 inches = 69 inches.
Activity levelA rough multiplier for total daily energy use. Frequency labels are approximations; exercise duration and occupation also matter.
Energy scenarioThis optional percentage scenario is educational, not a personal intake recommendation.
Scenario adjustmentSubtracts or adds this percentage to estimated maintenance. No weight-change timeline is predicted.
PUT THE FORMULA TO WORK

Worked examples you can try.

Load an example into the calculator, then change one value to explore.

EXAMPLE 01

See resting versus active energy

At 70 kg, 175 cm, age 30 and the male constant, estimated resting energy is 1,648.75 kcal/day. A 1.55 activity factor gives about 2,555.56 kcal/day.

EXAMPLE 02

Compare activity assumptions

Keep measurements fixed and switch from sedentary to lightly active. The table makes the activity multiplier’s effect visible without changing the resting-energy equation.

MAKE THE NUMBERS MAKE SENSE

Common mistakes to avoid

  • Using the resting-energy figure as though it were a personalized daily intake target.
  • Selecting an activity factor from exercise frequency alone.
  • Interpreting a percentage adjustment as a guaranteed change in body weight.
A LITTLE MORE CLARITY

Frequently asked questions

How are maintenance calories estimated?

The calculator estimates resting energy needs and multiplies by an activity factor from 1.2 to 1.9. Real energy needs vary with body composition, health and daily activity.

Who is this calculator for?

This estimate is intended for adults 20–100. It is not designed for children, pregnancy, breastfeeding or people with medical nutrition needs. Consult a qualified professional for individual guidance.

Can I use pounds and inches?

Yes. Choose Imperial and use total inches for height. Inputs are converted to kilograms and centimeters before applying the equation.

Why is the activity table different from my adjusted scenario?

The table compares maintenance estimates at each activity factor. The optional higher or lower percentage is applied only to your selected scenario.

Is the weekly value a weekly food plan?

No. It is seven times the daily mathematical illustration. It does not evaluate food quality, nutritional adequacy or individual medical needs.

Methodology & assumptions

Calculations run in your browser using the formulas and assumptions explained on this page. Intermediate values retain full floating-point precision; displayed amounts are rounded. Health results are adult educational estimates and do not replace an individual clinical or nutrition assessment. Sharing an input link places those inputs in the URL.

Further reading:Mifflin et al. original resting-energy research
KEEP EXPLORING

A little more perspective.

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