About LiftMath
LiftMath is the barbell arithmetic: your true one-rep max from any hard set, the percentage loads every program assumes, and where your strength-to-weight ratio ranks.
LiftMath exists because every strength program is written in percentages of a one-rep max that most lifters never safely test. The rep-max formulas (Epley, Brzycki) convert any hard set into that number — and the percentage table turns it back into training loads.
Every calculator on LiftMath shows its formula and its assumptions on the page, so you can check the math, reproduce it in a spreadsheet, or argue with it. Inputs are processed entirely in your browser — nothing is sent to a server, and there are no accounts.
LiftMath is an independent, ad-supported project. We are not affiliated with any lender, brand, agency, or the sources we cite (NIH and CDC public guidance). If a number looks wrong, the contact page reaches a human who fixes it.
What makes LiftMath different
- Your numbers never leave your browser. Every calculator on LiftMath runs entirely on your device. We never see, store, or transmit the figures you enter — there are no accounts and no server-side processing of your inputs.
- Published methodology. Each calculator page explains the exact formula it uses and the assumptions behind it, so you can check our work or reproduce it in a spreadsheet.
- Free, forever, without a paywall. LiftMath is supported by advertising. There is no premium tier, no email gate, and no upsell.
Independence
LiftMath is an independent educational project. We are not affiliated with, endorsed by, or acting on behalf of any government agency, lender, insurer, or the organizations whose formulas and public data we reference (such as NIH and CDC public guidance). All trademarks and referenced standards belong to their respective owners.
Questions, corrections, or suggestions are genuinely welcome — get in touch.