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How to Calculate Your Maintenance Calories (Step by Step)

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The formula gives you an estimate. To find your real maintenance calories, weigh yourself for 2-3 weeks while eating the same intake, then adjust.

Knowing your real maintenance calories is the most valuable data point in your nutrition: from there, everything else (deficit, surplus, recomp) builds itself.

The formula + verification method

Formulas have an average error of ±15 %. The right approach combines a formula as a starting point with real-world verification over 2-3 weeks.

Step 1: Estimate with a formula

Calculate your TDEE with Mifflin-St Jeor + activity factor. For example, 30-year-old man, 80 kg, 180 cm, moderate activity: BMR 1780, TDEE 2759 kcal.

Step 2: Eat exactly those calories for 14-21 days

Weigh food on a scale. Log everything in an app (Cronometer, MyFitnessPal). No eyeball estimates. No exceptions: Saturday binge eating skews the whole measurement.

Step 3: Weigh yourself every morning fasted

Record your weight when you wake up, after using the bathroom, with no clothes on. Use a 7-day rolling average to smooth out hydration and glycogen fluctuations.

Step 4: Adjust based on the trend

After 21 days, compare the rolling average from week one with week three.

Weight changeInterpretationAdjustment
+0.5 kg or moreYou ate above maintenanceLower by 200-300 kcal
−0.5 to +0.5 kgYou hit your maintenanceStay put
−0.5 kg or moreYou were in a deficitRaise by 200-300 kcal
In the first 1-2 weeks, glycogen and water retention can throw you off. That's why you adjust only after at least 2-3 weeks, not sooner.

Common mistakes when estimating calories

  • Not weighing oils and sauces (can hide 300 kcal).
  • Eyeballing portions instead of using a scale.
  • Forgetting 'flexible' weekends that shift your weekly balance.
  • Using a static maintenance TDEE after a major weight change.

About this guide

Last reviewed
. We review content at least once a year, and sooner if relevant literature comes out. Update policy.
How it is verified
We prioritize meta-analyses, systematic reviews and official positions (ISSN, ACSM, EFSA, WHO, Cochrane). Full methodology · topic: Nutrición y calorías.
Conflicts of interest
Some product links are affiliate links from Amazon España and earn us a small commission at no extra cost to you. How we fund the project.
Medical disclaimer
Educational content. Does not replace consultation with a healthcare professional. More detail.

Spotted an error in a formula or recommendation? Email us at jesus.narvaez.tames@hotmail.com. Corrections are published as an updated note on the guide.

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