One Rep Max Calculator
Calculate your estimated 1-rep max from any weight and rep combination. Get training percentages for strength programs.
One Rep Max Calculator on True Calculator gives you an instant, accurate answer with no sign-up and no app install. Calculate your estimated 1-rep max from any weight and rep combination. Get training percentages for strength programs. Every result shows the formula and a worked example so you can verify the calculation yourself, and all values are computed in your own browser — your numbers never leave your device.
Popular uses: one rep max calculator · 1rm calculator · max bench calculator
How We Calculate
This calculator uses standard mathematical formulas verified by our team. All calculations are performed instantly in your browser using JavaScript — no data is sent to any server. The formulas used are industry-standard and match those used by banks, financial institutions and health organizations.
For financial calculators, we use RBI-approved formulas and regularly updated bank rates. For health calculators, we use WHO-recommended formulas and medical standards. All rates and standards are sourced from official government and regulatory websites.
Frequently Asked Questions
You might also need
Related calculators from other categories
Math
Percentage Calculator
Calculate percentages, percentage difference and percentage change instantly. Work out what 20% of any number is, find discounts, markups and more.
Date
Age Calculator
Find your exact age in years, months and days from your date of birth — plus the weekday you were born on. Free and works offline.
Date
Date Difference Calculator
Count the exact number of days, weeks, months and business days between two dates. Perfect for deadlines, leave planning and projects.
Time
Time Duration Calculator
Calculate hours and minutes between two times, across midnight if needed. Ideal for shifts, travel time and event planning.