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Fitness and Health Calculators

One Rep Max Calculator

Lift performed

Estimated one-rep max

116.7 kg

Best accuracy with a challenging set of roughly 3–10 reps. Estimates vary by lift, skill, and individual response—use as a planning guide, not a competition standard.

Estimated max weight by repetitions

0316394125RepetitionsWeight
5101520

Repetitions → weight

RepetitionsWeight% of 1RM
1116.7 kg100%
2109.4 kg94%
3106.1 kg91%
4102.9 kg88%
5100.0 kg86%
697.2 kg83%
794.6 kg81%
892.1 kg79%
989.7 kg77%
1087.5 kg75%
1283.3 kg71%
1479.5 kg68%
1676.1 kg65%
1872.9 kg63%
2070.0 kg60%

Percentage of 1RM

% of 1RMWeightRepetitions
100%116.7 kg1
95%110.8 kg2
90%105.0 kg3
85%99.2 kg5
80%93.3 kg8
75%87.5 kg10
70%81.7 kg13
65%75.8 kg16
60%70.0 kg20
55%64.2 kg25
50%58.3 kg30

One Rep Max (1RM) Calculator Guide: Formulas, Tables, and Training Use

How to use

  • Select units (kg or lb) and enter the weight you lifted for a hard set.
  • Enter repetitions between 1 and 10 (values outside this range are less reliable for these formulas).
  • Choose Epley, Brzycki, or Lombardi and read the estimated 1RM.
  • Use the chart and tables to plan warm-up jumps, working sets, and percentage-based loads.
  • Re-run after a training phase when your strength has clearly changed.

Formulas (reference)

Epley: 1RM ≈ weight × (1 + reps/30). Brzycki: 1RM ≈ weight × 36/(37 − reps). Lombardi: 1RM ≈ weight × reps^0.10. Inverse mappings for the tables derive from the same formula so the chart matches your selection.

Guide

What one-rep max means

A one-rep max (1RM) is the most weight you can lift for one solid rep with good technique. Most people estimate it from a hard submaximal set instead of testing an all-out single—less risk, less time, and no need for a competition setup every week.

This page uses that same estimation idea as common tools such as https://www.calculator.net/one-rep-max-calculator.html.

What you get here

Enter the weight you used and reps you completed (about 1–10). Pick Epley, Brzycki, or Lombardi to produce an estimated one rep max, a bar chart of weight by rep count, and two reference tables for programming.

Reading the tables

The repetitions→weight table answers: “If my estimated 1RM is X, about how much weight for N reps?” The single-rep row stays at 100% so it lines up with typical reference layouts; other rows use the inverse of the formula you selected so the chart, tables, and headline number match.

The percentage table lists weights at common fractions of your estimated 1RM and a nearby rep count under the same formula. Treat those numbers as anchors—tempo, how close you train to failure, and weekly volume still change the outcome.

Lift-specific use and safety

Estimates are per exercise and setup: a bench 1RM does not transfer numerically to a squat or deadlift. Pause vs touch-and-go, bar height, and stance can all shift the number—track lifts separately when you care about precision.

You do not need true max testing to get stronger. If you do heavy singles, use warm-ups, spotters or safeties when appropriate, and stop when form breaks. A sloppy max is a poor data point and a needless injury risk.

Percentages, readiness, and trends

Programs often prescribe percentages of 1RM; they are easy to write down but sleep, stress, nutrition, and fatigue still change how heavy a given percentage feels. Adjust when bar speed or effort says so.

Beginners can change quickly; experienced lifters change more slowly. Either way, trends over several weeks matter more than updating the calculator after every session.

Practical topics

Why estimates differ between formulas

Each formula compresses real lifter data into a simple curve. None know your limb lengths, skill, or whether you stopped with one rep in reserve. If two formulas disagree by a few percent, that is normal. Use the estimate that tracks your real performance over time when you occasionally test heavier singles or AMRAP sets.

RPE and reps in reserve

Modern programs often use RPE or “reps in reserve” instead of fixed percentages. You can still use 1RM estimates to ballpark loads, then adjust session-to-session based on feel. The calculator is a starting point; autoregulation is the fine-tuning layer.

Warm-up strategy

Tables help space warm-up jumps. A common pattern is small jumps early, larger jumps mid-way, then singles near the working weight. Avoid excessive fatigue before heavy top sets while still preparing joints and the nervous system.

Equipment and comparing sessions

Bar stiffness, plate diameter, Smith machine vs free weights, and belted vs beltless work all change how a weight feels. When tracking estimated 1RM over months, keep equipment and range of motion as consistent as you can.

Deloads, fatigue, and missed reps

After an easy week you may feel stronger; after a hard block the same percentage can feel heavy. Use tables as a map, not a mandate. Repeated misses at programmed loads usually mean lighten the bar, recover, or fix technique—not force the spreadsheet.

Hypertrophy vs strength loading

Heavier, lower-rep work and moderate loads with reps in reserve can both build muscle depending on effort and volume. Two lifters on different percentages can create similar stress if effort differs. Your 1RM estimate is one input alongside volume, frequency, and exercise choice.

Coaching and solo lifting

A calculator output is not permission for a risky single. Good coaching combines numbers with movement quality and progression rules. Training alone? Prefer small jumps, use safeties, and use occasional video to check depth and bar path.

Who the formulas represent

Classic 1RM equations only see weight and reps—not sex, age, or training age—so individual error is normal. Consistent progressive overload, recovery, and joint-friendly technique matter more than chasing a perfect estimate.

Limitations

  • Not a substitute for coached max testing or medical clearance when needed.
  • Less reliable at very high rep counts for these classical formulas.
  • Does not replace technique coaching or fatigue management.
  • Lift-specific; do not generalize one 1RM across unrelated exercises.

FAQ

Which 1RM formula should I use?

Epley and Brzycki are the most common. If unsure, try both and see which tracks your occasional heavier tests better. Lombardi is a third viewpoint; larger differences at low rep counts are normal.

Can I use more than 10 reps?

These classical formulas target roughly 1–10 reps. Above that, estimates become less stable; consider a different model or test a heavier AMRAP in a safer rep range.

Is estimated 1RM the same as a competition max?

No. Competition attempts include arousal, commands, and standards. Training estimates are planning tools. Give yourself margin when moving from spreadsheet to platform attempts.