Tools
Each tool runs the same math the Deficit app uses internally, anchored on lean body mass rather than total weight.
-
Lean Body Mass Calculator
Calculate LBM with the Cunningham equation, then chain it forward to a protein target, body-fat-aware deficit, and an 8-week cycle plan. The most complete tool on the site.
-
TDEE Calculator
Find your maintenance calories with the same Cunningham + PAL + TEF math. Useful when you already know your LBM and just need the daily burn number.
-
Body Fat Percentage Calculator
Estimate body fat from a tape measure or skinfold calipers, then chain it into fat mass, lean mass, and a recommended cut deficit. The starting point when you don't know your body fat number.
Which one to start with
All three run on the Cunningham equation, which sizes your resting metabolism from lean body mass instead of total weight, so the numbers track your training rather than the scale. If you do not know your body fat yet, start with the body fat calculator and chain its result forward. From there, the lean body mass calculator is the most complete tool on the site: it gives you a protein target, a deficit sized to your composition, and an eight week cycle plan in one place. Use the TDEE calculator on its own when you already know your lean mass and just want the daily maintenance number. Every result carries the same citations and medical disclaimer as the app, works instantly as you type, and never asks for an email or stores what you enter.