Squat 1RM Calculator
A squat 1RM calculator built for the king of lifts. Enter your working weight and reps to get a three-formula 1RM estimate, the plates to load per side, and a full percentage chart for programming squat volume. Depth matters: estimate from sets done to competition depth for numbers you can trust.
Result
| Epley | |
| Brzycki | |
| Lombardi |
Plates per side (to load the estimated 1RM)
Percentage chart
Formula & source
Brzycki: 1RM = w × 36 / (37 − r)
Lombardi: 1RM = w × r0.1
Reported max = mean of the three
Sources: Epley (1985), Brzycki (1993), and Lombardi (1989) — the three most-cited rep-max formulas in strength literature. All three are rep-based estimates, most accurate for sets of 1–10 reps; beyond 12 reps the error grows and the calculator clamps reps to 12. Unique to this page: all three formulas are shown side by side instead of hiding behind one number, so you can see the spread and judge the uncertainty yourself. Unique to this page: squat-specific guidance — estimates are only comparable when sets are done to the same depth; high-bar vs low-bar changes leverages and therefore the number.
Worked example (you can verify by hand)
Input: 225 lb × 5 reps, 45 lb bar.
- Epley: 225 × (1 + 5/30) = 262.5; Brzycki: 225 × 36/32 = 253.1; Lombardi: 225 × 50.1 = 264.3
- Average 1RM ≈ 260.0 lb
- Per side: (260 − 45) / 2 = 107.5 → 45×2 + 10 + 5 + 2.5
Expected output: ≈ 260 lb 1RM; load 2×45 + 10 + 5 + 2.5 per side.
Limitations — what this cannot do
- Estimates, not measurements — only a true 1RM test (or meet total) is exact; formulas typically land within ±5% for sets under 10 reps.
- Technique, fatigue, sleep and warm-up change the real number day to day; retest or recalculate every 4–6 weeks.
- Not for beginners attempting maximal singles without a spotter and coaching — build base volume first.
- High-bar, low-bar, front and box squats are different lifts — do not mix rep data across variations in one estimate.
Disclaimer: Estimates for training planning only, not medical advice. Consult a professional.
FAQ
Does squat depth change the 1RM estimate?
Yes. A 5-rep set to parallel estimates a parallel 1RM; the same weight done high will overestimate your competition-depth max. Keep depth consistent between test sets and attempts.
High-bar vs low-bar — which number counts?
Both are real, they are just different lifts with different leverages. Track them separately and estimate each from its own rep data.
How often should I retest my squat max?
Every 8–12 weeks is plenty for most lifters. Between tests, recalculate from a heavy AMRAP set — safer and less disruptive than maxing out.
Why does my squat estimate feel high?
Estimates from bouncy or shallow reps overshoot. If the number feels wrong, it usually is: retest with strict depth and a 2-second pause.