One-Rep Max Calculator.

For 2–10 repetitions: estimated 1RM = weight × (1 + repetitions ÷ 30). For one rep, the entered load is shown as a recorded single—not proof that it was a true maximum. The estimate is more uncertain with higher repetitions, fatigue or sets far from failure, and may fit some exercises poorly. No attempt at the predicted maximum is recommended.

Displayed values are rounded to at most six decimal places unless otherwise noted. Plate totals are calculated from your entered equipment, not from rounded display values.

Software limits are input guardrails, not a declaration that a load is safe for you. Stop for pain; do not chase a number at the expense of technique.