1RM Calculator
Enter any set you performed — weight, reps, and RPE — to estimate your one-rep max and training maxes using three independent methods.
Results
Estimated 1RM
Training Maxes (from RTS estimate)
Enter a weight above to see your estimates.
Which formula should I trust?
The RTS / RPE-based estimate uses the Reactive Training Systems chart co-developed by Mike Tuchscherer. It accounts for your effort level (RPE), making it the most specific to how you actually performed the set. Use this as your primary reference.
The Epley and Brzycki formulas are classical equations that only use weight and reps — no RPE input. They tend to over-estimate for higher rep sets. The consensus average smooths out the variance between methods.
For programming purposes, your Training Max (TM) is typically set at 90–92.5% of your estimated 1RM. This gives a buffer for daily performance variation.