Weight Gain Calculator

Estimate maintenance calories, a modest surplus and rough target time.

How Weight Gain Calculator works

Estimate maintenance calories, a modest surplus and rough target time. The calculator uses a transparent formula and keeps the calculation in your browser.

BMR is estimated with Mifflin–St Jeor; TDEE = BMR × activity factor.

Example

Enter realistic values, calculate, then review the formula and supporting statistics shown with the result.

Understanding the result

A calculator gives an estimate based on its assumptions. Real-world outcomes can differ because inputs and circumstances change.

The surplus and timeline are illustrative estimates, not a medical or nutrition prescription.

Frequently Asked Questions

Are calculator results exact?

They are estimates based on the selected formula and the values you enter.

Does the website send my calculation to a server?

The calculator logic runs in your browser and does not require an external calculation API.