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Long-tail 1RM calculator

Squat 1RM Calculator with Confidence Interval

Estimate your squat 1RM from a clean working set, compare seven formulas, and use the confidence interval to choose conservative squat training loads.

7 formulas
Confidence interval
Training advice

Use a depth-consistent set; high-bar and low-bar estimates may differ.

Estimated 1RM

367.5 lb
Back Squat using Epley

Recommended training max

330 lb
90% standard. Good default for 5/3/1-style percentage work.

Formula spread

354.4-374.9 lb
20.5 lb / 5.6%

Best use

Use selected TM
Recommended: Epley with 90% training max is a usable programming number.

Formula range

354.4-374.9 lb

Spread: 20.5 lb / 5.6%

Lowest: BrzyckiHighest: Mayhew

Training max guidance

Use the recommended training max for multi-week programs. Current load rounding uses 5 lb jumps and nearest rounding.

Sustainable range: 310-345 lb. Pick the lower end when reps are high, the spread is wide, or the set used RIR adjustment.

Scroll table horizontally

PercentLoadRoundingRepsPurposePlates
100%370 lb+2.5 lb1Max strengthLoad
95%350 lb+0.9 lb2Max strengthLoad
90%330 lb-0.7 lb3-4Max strengthLoad
85%310 lb-2.4 lb5-6StrengthLoad
80%295 lb+1 lb7-8StrengthLoad
75%275 lb-0.6 lb9-10HypertrophyLoad
70%255 lb-2.2 lb11-12HypertrophyLoad
65%240 lb+1.1 lb13-15Technique or enduranceLoad
60%220 lb-0.5 lbAMRAPGeneral workLoad
55%200 lb-2.1 lbAMRAPGeneral workLoad
50%185 lb+1.3 lbAMRAPGeneral workLoad
Build training maxGenerate warm-upsBuild 5/3/1 waveLoad plates

URL updates as you change inputs.

Recent estimates

Save a result to track your estimated max by lift on this device. Nothing is uploaded.

Squat 1RM confidence interval

For a default example of 315 lb x 5, the seven formulas produce a practical confidence interval of 354.4 lb - 374.9 lb, with a formula mean of 363.8 lb.

Use this range as the answer, not a single number. If the set was clean and low-rep, the middle of the range is reasonable. If technique changed or reps were high, use the lower end and build a training max from there.

Suggested training range: about 300 to 345 lb, before rounding to plates and adjusting for recovery.

Scroll table horizontally

Formula Calculation Estimate Use it as
Epley 315 x (1 + 5 / 30) 367.5 lb Optimistic side of the range
Brzycki 315 x 36 / (37 - 5) 354.4 lb Conservative side of the range
Lombardi 315 x 5^0.10 370 lb Optimistic side of the range
O'Conner 315 x (1 + 0.025 x 5) 354.4 lb Conservative side of the range
Mayhew 100 x 315 / (52.2 + 41.9 x e^(-0.055 x 5)) 374.9 lb Optimistic side of the range
Wathan 100 x 315 / (48.8 + 53.8 x e^(-0.075 x 5)) 367.2 lb Optimistic side of the range
Lander 100 x 315 / (101.3 - 2.67123 x 5) 358.2 lb Conservative side of the range

How to estimate your squat 1RM

Squat 1RM estimation depends on consistent depth, stance, bar position, belt use, and shoe choice. A clean triple to six-rep set is usually a better input than a long set where depth or bracing fades.

The calculator above keeps the same input set and shows seven formulas side by side: Epley, Brzycki, Lombardi, O'Conner, Mayhew, Wathan, and Lander. For squat, use the formula spread as the confidence signal. Tight spread means the set is probably useful; wide spread means the input was too high-rep, too technical, or too inconsistent.

What is a good squat 1RM?

These bodyweight multiples assume a full-depth raw squat with a consistent standard. Low-bar, high-bar, belted, beltless, sleeved, and wrapped numbers should be tracked separately.

Scroll table horizontally

Lifter level Bodyweight 1RM ratio Example
Untrained 0.75-1.0x 135-180 lb for a 180 lb lifter
Novice 1.0-1.25x 180-225 lb for a 180 lb lifter
Intermediate 1.25-1.75x 225-315 lb for a 180 lb lifter
Advanced 1.75-2.25x 315-405 lb for a 180 lb lifter
Elite 2.25x+ 405+ lb for a 180 lb lifter

Squat 1RM notes

  • Use the same depth standard every time you estimate.
  • Keep high-bar, low-bar, belted, beltless, and wrapped estimates separate.
  • Use a conservative formula when a set includes any questionable depth or bracing breakdown.

A squat estimate is only as honest as the depth standard behind it. If the input set was high, the calculator can still produce a number, but that number should not be treated as a full-depth 1RM.

Low-bar squats often produce higher estimates than high-bar squats for the same lifter because they change leverage and muscle contribution. That does not make one better; it means the estimate belongs to that variation.

Squat fatigue can make percentage work feel heavier than the table suggests. If 85% work turns into grinding singles, use 90% of the estimated max as a training max and build the block from there.

Programming with your squat 1RM

Use the estimated max to choose a conservative training max before writing the block. For most healthy adult lifters, 90-95% of estimated 1RM is enough. If the set was high-rep, grindy, or technically inconsistent, use 85-90% instead.

Scroll table horizontally

Goal Working % Sets x reps Note
Strength 82.5-92.5% 3-6 sets of 1-5 reps Heavy enough for skill practice without turning every week into a test.
Hypertrophy 65-80% 3-5 sets of 6-12 reps Useful for high-bar, beltless, or tempo work.
Technique 55-70% 4-8 sets of 2-5 reps Pause, tempo, and speed work should stay crisp.

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