Tool · Calculator

1RM
Calculator

Enter a weight and a rep count: the calculator estimates your one rep max and works out your training weights for each goal.

  • Epley formula
  • Weights by goal

1RM Calculator

Enter the weight lifted and number of reps performed

Your 1RM (one rep max) is the heaviest weight you can lift for a single rep on a given exercise. Training weights are often set as a percentage of it, and it's a simple way to see whether your strength is going up.

The calculator estimates it with the Epley formula, using a set you've already done. That way you don't have to test your true max, which is exhausting and riskier.

What is 1RM?

A strength measure

It's the standard measure in powerlifting, and the easiest way to compare your strength on the same lift from one period to the next.

Programming tool

Many programs give weights as a percentage of 1RM. Knowing yours, even as an estimate, lets you apply them to your goal (strength, hypertrophy, endurance).

Progress tracking

Recalculating your estimated 1RM every 6-8 weeks shows whether your strength is moving, and which lifts need a change in the program.

Less risk

An estimate means you never have to load the bar to your max. A max test is very tiring and raises the risk of injury, especially if your technique isn't solid yet.

Good to know: the calculated 1RM is still an estimate. It's most reliable from a set of 3 to 8 reps taken close to failure. Past 10 reps, muscular endurance starts to matter and the result gets less accurate.

Follow your 1RMs in BenchRep

How to use your 1RM

1 Calculate your training loads

With your 1RM, you can set the weight for each session as a percentage, depending on your goal.

Maximum strength (1-3 reps): 90-95% of 1RM
Strength (3-5 reps): 85-90% of 1RM
Hypertrophy (6-12 reps): 70-85% of 1RM
Endurance (12-20 reps): 60-70% of 1RM

2 Program your training cycles

An example 12-week cycle that gradually shifts from volume to intensity:

Weeks 1-4

  • • 70-75% of 1RM
  • • 4 sets of 8-10 reps
  • • High volume

Weeks 5-8

  • • 80-85% of 1RM
  • • 4 sets of 5-6 reps
  • • Medium intensity

Weeks 9-12

  • • 85-95% of 1RM
  • • 3-5 sets of 1-3 reps
  • • Maximum intensity

3 Measure your progression

Recalculate your estimated 1RM every 6-8 weeks. As a rough guide, on the big lifts:

  • Beginners

    Fast progress: roughly +10-20 lbs every two months

  • Intermediate

    Moderate progress: +5-10 lbs every two or three months

  • Advanced

    Slow progress: +2-5 lbs every three to six months

4 Compare your performances

Strength standards tables show where you stand on the basic lifts. The numbers vary between sources, so treat them as rough markers.

Bench press, 176 lb man, ballpark figures:

Beginner: 132-154 lbs
Intermediate: 176-220 lbs
Advanced: 242-287 lbs
Elite: 308+ lbs

The app

Your estimated 1RM, tracked in BenchRep

After every workout, BenchRep GymTracker picks up your new records, estimated 1RM included, and each exercise has a chart that shows how it changes. The app is available on the App Store and Google Play.

Download, €8.99 once

Safety tips

  • Warm up in steps

    Before working heavy or testing a 1RM, do 3 or 4 warm-up sets, adding weight each time and doing fewer reps as you go.

  • Never test alone

    On the bench press and the squat, get someone to spot you or set the rack's safety bars at the right height.

  • Master technique first

    Only test your 1RM on a lift you know well. When form breaks down under a maximal weight, the injury risk goes up sharply.

  • Prefer estimations

    To follow your strength from week to week, a set of 3-5 reps run through the calculator is enough. Keep true max tests for rare occasions.

  • Respect recovery

    If you do test your true 1RM, leave at least 6-8 weeks between tests. A max effort leaves you tired for days, and frequent tests take the place of useful training.

Frequently asked questions

What formula does the calculator use?

The Epley formula: 1RM = Weight × (1 + Reps/30). It's one of the most widely used. Up to about ten reps it gives results close to the Brzycki formula, and it gets less reliable past that.

Should I test my real 1RM?

Not to make progress: an estimate is enough to set your training weights. A real test mostly makes sense before a competition or if you want an exact number, once or twice a year at most.

Does the calculator work for all exercises?

On most of them, but it's more accurate on compound lifts (squat, bench press, deadlift, overhead press). On isolation exercises, muscular endurance plays a bigger part and the estimate is less reliable.

My 1RM isn't increasing anymore, what to do?

It happens to everyone after a few months. Start with sleep, food and recovery. After that, you can add a little volume, switch to a variation for a few weeks or run a strength-focused cycle (85-95% of 1RM). In a calorie deficit, it's normal for strength to move slowly.

How often should I recalculate my 1RM?

Every 6-8 weeks, or at the end of each training cycle. In BenchRep, the estimated 1RM is one of the records detected after every logged workout, so there's nothing to recalculate by hand.

Your estimated 1RM, workout after workout

BenchRep GymTracker is available on the App Store and Google Play. After every workout, the app picks up your records, estimated 1RM included, and the built-in coach suggests today's weight based on your last session. €8.99 once, no subscription, no account.

Download on the App Store Get it on Google Play
  • 618 exercises, 602 with a video
  • 15 programs included
  • Works offline
  • No account needed