Cambered-Bar vs Regular Bench Press Calculator
Cambered-bar bench press
Estimated weight for 1 reps
Enable JavaScript to calculate. The study inputs, formulas and limitations below remain readable without JavaScript.
Study inputs and scope
Range of motion of resistance exercise affects the number of performed repetitions but not a time under tension. — Study authors (2021).
- Reported mean 1RM loads from the linked study.
- Mean regular barbell bench press 1RM: 140 kg.
- Mean cambered-bar bench press 1RM: 133 kg.
This ratio is calculated here from the reported group-average 1RMs. It is not an individual prediction equation published by the researchers.
The tested cambered bar allowed increased range of motion. This is not a partial-ROM or generic specialty-bar conversion. Bar geometry and achieved depth must match the study before applying the estimate; include the actual bar mass.
Conversion formula
Regular barbell bench press 1RM (barbell load) = Cambered-bar bench press 1RM (barbell load) ÷ (133 / 140)
The model’s ratio is 0.950000000, or approximately 95.00% for combined target load relative to combined starting load in the first-to-second direction. The reciprocal is used for the reverse direction.
The same ratio works in lb and kg when both sides use consistent units. Automatically populated inputs display nearest 1 lb or 0.5 kg while retaining precision internally. Only the final displayed weight is rounded; dumbbell results are rounded per hand before showing the combined load.
How input and target reps are estimated
When you enter more than one rep, the calculator uses the site’s existing Epley method to estimate the starting exercise’s 1RM. It then applies the exercise ratio and estimates a weight for your chosen target reps. This rep conversion is an additional modeling assumption; the study comparison does not validate every possible source/target rep combination.
Source 1RM = weight × (1 + source reps ÷ 30) (for 2–20 reps)
Target rep weight = target 1RM (for 1 rep)
Target rep weight = target 1RM ÷ (1 + target reps ÷ 30) (for 2–20 reps)
Both rep counts can independently range from 1 to 20. Use comparable effort and consistent technique. Higher-rep estimates are more sensitive to individual endurance.
How to interpret the estimate
The multiplier is a ratio of group means, not a validated individual prediction equation. The reverse direction uses its reciprocal.
Individual results vary with technique, training experience, equipment, and range of motion.
No sex-specific, experience-specific or rep-specific exercise multiplier is applied. A study sample does not establish a universal conversion for every lifter. This page does not display a statistical confidence interval or a guaranteed training load.
Switching the starting exercise carries the unrounded target-rep estimate into the other exercise and swaps the source and target rep counts. Rounding affects only the displayed results.
Source notes
The study details and numerical inputs incorporate a user-supplied source-verification report. Primary documents remain inaccessible in this environment, so independent full-text verification is pending. Scope and reporting ambiguities are stated above.