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One Rep Max Calculator

Estimate your 1RM from any rep set. Includes a percentage table for programming squats, bench, deadlift, and any compound lift.

  • Runs in your browser
  • Private processing
  • No uploads
Your set
kg
reps
Estimated 1RM
Enter weight and reps to estimate your 1RM

01Why this 1RM tool

Estimate without testing.

Four reasons coaches and lifters use this page to program safer, smarter blocks.

  • 01

    Epley, Brzycki, and Lander — together

    Three of the most validated 1RM formulas displayed side by side. Pick whichever matches your gym, your coach, or the spreadsheet you've been using.

  • 02

    Training percentages built in

    From the calculated 1RM, the tool generates a 50%–100% table — perfect for programming back-off sets, RPE work, or percent-based mesocycles.

  • 03

    Kilograms or pounds

    Toggle the unit your bar plates are in. Output stays in the same unit so there's no conversion in your training journal.

  • 04

    Calculates locally

    Weights and reps stay in your tab. The tool doesn't track or transmit your numbers.

02How it works

One set, a whole block.

  1. Top set
    Weight140kg
    Reps5

    Step 1Enter your heavy set

    The weight you lifted and how many clean reps you got. Sets in the 1–10 rep range produce the most accurate 1RM estimates.

  2. Formula
    EpleyBrzyckiLander

    Step 2Pick a formula (or compare)

    Epley is the common default. Brzycki tends to slightly underestimate at high reps; Lander sits between the two.

  3. Estimated 1RM162kgPercentages 50%–100% ready

    Step 3Read your 1RM and percentages

    Estimated 1RM plus a table of training weights from 50% to 100%. Drop the percentages directly into your program.

03Use cases

Where 1RM math earns its keep.

Mesocycle planning, peaking, ratio checks — anywhere percentages matter.

  • Set up a 5/3/1 mesocycle

    Start with a 5-rep PR on each lift, calculate the training max, build your weeks from the percentage table.

    Bench 5RM → 90% training max

  • Estimate from a recent AMRAP

    Finished a top set with reps in reserve? Plug in the rep count to estimate the real 1RM without re-testing.

    Deadlift AMRAP → safe 1RM

  • Compare your three lifts honestly

    Estimate squat, bench, and deadlift 1RMs from your current working sets to check ratios and rebalance weak points.

    S/B/D ratios at a glance

  • Plan a peaking block

    Top out at 95% one week, 100% the next. Knowing the absolute load lets you build the run-up backwards from goal day.

    Peak week · 100% target

  • Coach handoff

    Send a lifter their percentage table for a new block. They train off the table; you train them, not arithmetic.

    Athlete training table

  • Avoid a max-test injury

    Reps in the 3–6 range yield very accurate 1RM estimates — without the spinal load of a true single. Lower-risk progress tracking.

    3RM → estimated 1RM

04Quick tips

Get a trustworthy 1RM.

Four habits to make the estimate match what you'd actually hit.

  • 01

    Stay under 10 reps for accuracy

    1RM formulas drift fast above 10 reps. Use sets in the 3–8 rep range for the most trustworthy estimates.

  • 02

    RPE matters

    A grindy 5-rep set at true failure gives a different 1RM than a 5-rep set with 2 reps in reserve. Be honest about effort.

  • 03

    Compare formulas for outliers

    If Epley and Brzycki disagree wildly, the rep count is probably high or the set wasn't to failure. Re-check your data.

  • 04

    Re-test every 6–12 weeks

    1RM drifts with training age. Plug in a fresh top set every block so percentages stay calibrated to where you are now.

05Loved by

Lifters, coaches, and recreational athletes.

  • Set up my prep block from a 3RM bench in two minutes. The percentage table fills the whole training program for me.
    Reyna G.
    Powerlifter
  • Estimating client 1RMs without making them test. Safer, faster, and the table I screenshot fits straight into their plan.
    Aiden B.
    Strength coach
  • Used to guess training weights. Now I plug in last week's top set and the table tells me exactly what to load.
    Olivia C.
    Recreational lifter

06Questions

1RM math, plainly answered.

Questions before your first table. Missing one? hello@wirelogs.com.

01Which formula is most accurate?

Epley and Brzycki track real 1RMs to within ~5% in the 3–8 rep range. They disagree more at higher reps. For programming, use the same formula every time so your percentages compare to past blocks.

02Why three formulas instead of one?

Different lifts and lifters respond slightly differently to each formula. Comparing all three is a useful sanity check before you load a real 1RM attempt.

03Can I use this for the snatch or clean & jerk?

The formulas are validated for slow-grind lifts (squat, bench, deadlift, OHP). Olympic lifts depend more on technical execution than absolute strength — use them as a rough guide only.

04How accurate is the percentage table?

Accurate enough that most coached programs are written off the same numbers. Trust them for 60–85% training work; verify yourself at 90%+ before relying on the estimate.

05Is my data sent anywhere?

No. Calculations are local. Your training log stays yours.

06Is it free?

Yes. No sign-up, no usage cap, no watermark.

07Related tools

Other training calculators.

1RM lives next to TDEE, pace, zones, and the rest of the fitness math.

Ready when you are

Plug in one heavy set.

Enter weight and reps above. Estimated 1RM and a full percentage table appear instantly.

Open the calculatorBrowse all tools
  • 3 formulasside by side
  • 50–100%percent table
  • $0now and always