Strength Training
22 calculators
Strength calculators covering one-rep-max estimation, the coefficients that make lifts comparable across body weights and ages, loading arithmetic, and session structure.
Most of what follows depends on one estimate: a one-rep max inferred from a submaximal set. Several published formulas do that inference, and they disagree with each other in a way that grows with repetitions.
- Barbell Plate Calculator (kg) Calculate the exact plate combination needed per side to hit your target barbell weight in kilograms.
- Barbell Plate Calculator (lbs) Calculate per-side plate loading to hit your target barbell weight with standard Olympic plates.
- DOTS Score Calculator Normalize powerlifting totals across bodyweight and sex using the IPF's DOTS coefficient system.
- Multi-Formula 1RM Comparison Calculator Compare Epley, Brzycki, and Lombardi 1RM predictions side-by-side from a single lift.
- One-Rep Max Calculator (Brzycki Formula) Estimate your one-rep max from sub-maximal lifts using the Brzycki (1993) formula.
- One-Rep Max Calculator (Epley Formula) Estimate your one-rep max from submaximal lifts using the classic Epley formula.
- Strength Standards Percentile Calculator Compare your lift to body weight and see which strength tier you fall into.
- Wilks Score Calculator Compare powerlifting totals across body weights using the 2020 Wilks coefficient.
- Workout Planner Build a 7-day training week from 160+ exercises and see weekly sets per muscle add up against the volume target you set.
- IPF GL Points Calculator Calculate IPF Goodlift points for raw powerlifting totals adjusted by body weight and sex.
- Masters Age Coefficient Calculator (McCulloch) Apply McCulloch masters age coefficients to a lifting total for age-adjusted comparison.
- One-Rep Max Calculator (Lombardi Formula) Estimate your one-rep max from submaximal lifts using the Lombardi formula.
- One-Rep Max Calculator (OConner Formula) Estimate your one-rep max using the OConner linear regression formula for sub-maximal lifts.
- One-Rep Max Calculator (Wathen Formula) Estimate your one-rep max using the Wathen (1994) nonlinear regression formula.
- Rep Max Calculator (Any Rep Max) Estimate your X-rep max from your known 1RM using the reverse Epley formula.
- RPE to Percentage Converter Convert RPE and rep count into estimated percentage of one-rep max using standard intensity tables.
- Sinclair Coefficient Calculator Compare Olympic weightlifting totals across bodyweight categories using the IWF Sinclair formula.
- Time Under Tension Calculator Compute total time under tension from sets, reps, and a four-digit lifting tempo.
- Training Intensity Percentage Calculator Calculate working intensity as a percentage of one-rep max
- Training Volume Load Calculator Calculate total training volume load from sets, reps, and weight lifted.
- Vertical Jump Power Calculator Convert a vertical jump into watts with the Sayers, Harman, and Lewis equations side by side.
- Warm-Up Set Calculator Generate a four-set percentage-based warm-up ramp for barbell lifts, rounded to plate increments.
One-rep max formulas and where they separate
Epley, Brzycki, Lombardi, O'Conner and Wathen all convert a weight and a repetition count into an estimated single. At five repetitions they agree closely — 100 kg for 5 returns figures between about 112 and 118 kg across them. Past ten repetitions they diverge sharply, because the relationship between repetitions and load stops being close to linear and each formula handles the curve differently.
The practical consequence is that a set of 12 gives a much less reliable estimate than a set of 3, regardless of which formula is applied. Running several formulas on the same set shows the size of that uncertainty rather than hiding it behind one number.
RPE-to-percentage tables take a different route to the same place, mapping a rating of perceived exertion and a repetition count onto a percentage of maximum, which sidesteps the formula question but introduces the accuracy of the rating instead.
Comparison coefficients and loading arithmetic
Wilks, DOTS, IPF GL points and the Sinclair coefficient all exist to compare lifts across body weights, because absolute load scales with mass while relative strength does not. Each fits a different curve to a different competition dataset, so the same lifter can rank differently under each. The masters age coefficients add a second adjustment for age, derived from age-group performance data.
The loading calculators are arithmetic rather than estimation: plate calculators solve which plates make a target bar weight from a given set, warm-up sets divide a working load into a ramp, and intensity percentage converts between a percentage and an absolute load. Volume load and time under tension summarise what a session accumulated.
Common questions
Which one-rep max formula is most accurate?
No single formula is consistently closest, and the choice matters less than the repetition count behind it. All of them are fitted curves, and they agree within a few kilograms at three to five repetitions while diverging substantially past ten. A set of 3 at a known weight produces a more reliable estimate under any formula than a set of 15. The comparison tool runs five formulas on the same set so the spread is visible.
Why do Wilks and DOTS give different rankings?
They fit different curves to different datasets. Wilks was derived from earlier competition data using a fifth-order polynomial, while DOTS was fitted later to a different sample and behaves differently at the extremes of body weight, particularly for lighter and heavier lifters. IPF GL points uses another approach again. Each is internally consistent, so a comparison is only meaningful when everyone in it is scored under the same coefficient.
How many warm-up sets should come before a working set?
Warm-up protocols are usually described as a ramp of progressively heavier sets with falling repetitions, and published examples commonly use three to five steps between an empty bar and a working load. The calculator here divides a given target load into a ramp using a stated pattern of percentages rather than prescribing a number; the pattern it uses is shown alongside the result.