Strength
Velocity-Based 1RM Estimator
Estimate one-rep max from the bar speed of one set: published load-velocity equations for squat and bench, approximate lines for deadlift and overhead press.
Result
Estimated 1RM and its likely range
Load ÷ (%1RM ± 2 standard errors of the load-velocity equation).
Training zone at this speed
Strength-speed
Bar-speed zones
- Max strength: 0.15–0.45 m/s, absolute strength
- Strength-speed: 0.45–0.65 m/s, strength under speed
- Speed-strength: 0.65–0.95 m/s, explosive intent
- Starting strength: 0.95–1.50 m/s, speed development
The formula, worked through
- Formula RPE to Percentage Formula (Tuchscherer)
RPE to percentage formula: the Tuchscherer (RTS) chart maps reps × RPE to a share of 1RM; RPE 8 for 5 reps is 81.1%. Worked squat example and the RIR scale.
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Articles
- 7 min read How to Estimate a 1RM Without Testing for One
Estimate a 1RM without testing: Epley, Brzycki, Lombardi, O'Conner, Wathan, and Mayhew — error bands, rep-range fit, and safety.
- 6 min read Bench Press RPE 8 for 5 Reps: The Percentage Walkthrough
Bench press RPE 8 for 5 reps maps to 81.1% of 1RM on the RTS table. For a 140 kg bench 1RM that is 113.5 kg. The math and the velocity cross-check.
- 7 min read Velocity-Based 1RM: 180 kg Squat at 0.50 m/s in Practice
Velocity-based 1RM math: 180 kg squat at 0.50 m/s estimates 200.2 kg (likely 183-221 kg). The strength-speed zone read and where bar speed lies.
Use it from an agent or code
Any agent can run this calculator by URL: put the inputs in the query string and get JSON back, with the inputs that used defaults and a line to cite (add format=md for markdown). MCP clients reach it through https://aifithub.io/mcp.
https://aifithub.io/api/run/velocity-based-1rm?bar_speed_m_per_s=0.5&weight_kg=100&lift_type=squat
In code, import the same module; it runs where you import it, with no request or key.
import { compute } from "https://aifithub.io/engines/velocity-based-1rm.js";Input and output contract, TypeScript types and the guide for agents.