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1RM Back Squat Calculator — Estimate Your Max (Epley Formula)

Q: What's the Epley formula for 1RM and how accurate is it?

**Epley (1985): 1RM = Weight × (1 + Reps ÷ 30)**. At 3–6 reps the formula is typically within ±2–5% of a true max. Above 10 reps accuracy drops to ±10–15%. The Epley equation is used in virtually every strength program (5/3/1, Sheiko, Smolov) as the de facto standard for estimating 1RM from submaximal sets.

Q: What's a strong squat for a woman at 145 lb bodyweight?

Strength standard bands: **novice ~125 lb**, **intermediate ~175 lb**, **advanced ~235 lb**, **elite ~290 lb**. A 2× bodyweight squat (290 lb) at 145 lb places a female lifter very competitively at USAPL 63–69 kg meets.

Q: How often should I squat — once, twice, or more per week?

Depends on the program: Wendler 5/3/1 runs **once a week** heavy plus an optional lighter day. Texas Method uses **3× per week** (volume Monday, light Wednesday, intensity Friday). Sheiko runs **2–3 squat sessions/week**. For most intermediate lifters, **2 sessions/week** (one heavy, one volume) hits the sweet spot without compromising recovery.

Q: What's the typical high-bar to low-bar squat ratio?

Most trained lifters move **5–12% more weight low-bar than high-bar**. A 405 lb high-bar squat usually translates to about 425–455 lb low-bar once technique is dialed in. The gap is larger for taller lifters with long femurs.

Q: Should I test a true 1RM or trust the calculator?

For 90% of lifters in 90% of training blocks: **trust the calculator**. A true 1RM eats 7–10 days of recovery, needs a 45–60 min warm-up, and carries real injury risk. Reserve direct 1RM testing for competition day or once every 8–12 weeks. Use 3RM or 5RM retests every 4 weeks — that's what 5/3/1 and Juggernaut are built around.

Q: How long does it take to recover after a max squat test?

Plan on **5–10 days of reduced volume and intensity** after a true 1RM squat. Days 1–3: mobility work, very light bike. Days 4–6: 50–65% bar work, no AMRAPs. Day 7+: ramp back to 75–85% working sets. Even elite lifters (Ed Coan, Kirk Karwoski training logs) show ~10 days of dialed-back volume after meet-day attempts.

Q: What if I'm a beginner and don't know my top set?

Don't test a 1RM. Run **Starting Strength** or **StrongLifts 5×5** for 12 weeks and let linear progression reveal your 5RM. Once you stall on linear progression (usually around bodyweight × 1.2–1.5 squat), plug the last successful 5×5 set into the calculator — that gives a reliable estimated 1RM to build the next program on.

Enter weight and reps to instantly estimate your back squat 1-rep max using the Epley formula. Includes a %1RM table and strength standards for novice to elite lifters.

Data verified · June 2026
Edited by Martín Rodríguez
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The back squat 1RM is the single most useful number a lifter can carry around — it sets the loading for every working set, picks meet attempts, and benchmarks whether your last training block actually moved the needle. This estimator runs your top set (weight × reps) through the Epley equation, 1RM = w × (1 + r/30), the same predictor used by Wendler's 5/3/1, Sheiko templates, and most coach spreadsheets. Two other equations get cited a lot: Brzycki (w × 36/(37 − r)), which trims a couple of pounds off Epley and tends to match true singles better at 6+ reps, and Lombardi (w × r^0.10), which overshoots once you push past 8. None of these care whether you squat high-bar Olympic style or low-bar powerlifting — but your numbers will. Low-bar usually moves 5–12% more weight than high-bar for a trained lifter, so plug in whichever stance you actually compete in. For reference points: ExRx and Stronger by Science strength standards put a novice male squat (200 lb bodyweight) around 230 lb, an intermediate lifter around 315 lb, advanced around 405 lb, and elite/competitive at 500 lb+. For women at 145 lb bodyweight, those bands run roughly 125 / 175 / 235 / 290 lb. Use the calculator to set your next training cycle without having to grind a true single under a bar that hates you.

When to use this calculator

Picking USAPL or USPA meet attempts from training PRs — opener at 90–92% of your estimated 1RM (e.g., 405 lb predicted → 365 lb opener), second at 96–98% (390 lb), third at 100–103% (405–415 lb) so you don't bomb out on squat
Setting your training max (TM) for Wendler 5/3/1 — Jim's rule is TM = 85–90% of estimated 1RM, so a 500 lb predicted squat runs the cycle off a 425–450 lb TM (Week 3 top set: 95% TM = 405–428 lb × 1+ AMRAP)
Running a peak strength block at 85–95% 1RM (heavy doubles and singles in the 4 weeks before a meet) without a true max test eating recovery you don't have
Programming a hypertrophy phase at 65–75% 1RM for 8–12 rep sets — e.g., 405 lb 1RM → 265–305 lb working sets for 4×10 quad-focused volume
Sanity-checking a recent paused squat PR — if you grind out 315 × 5 paused, that's a ~365 lb paused 1RM; comparing it to your touch-and-go 1RM tells you how much your stretch reflex is buying you
Tracking Bulgarian-method daily max work — re-estimating projected 1RM weekly from your daily top single + back-off rep work, so you can spot stagnation before it becomes overreaching

1RM Prediction Formulas Compared — 100 kg × 5 Reps Example

Formula	Equation	Result (100 kg × 5 reps)	Best accuracy range
Epley (1985)	w × (1 + r/30)	116.7 kg	1–10 reps
Brzycki (1993)	w × 36 / (37 − r)	112.5 kg	6+ reps (more conservative)
Lombardi (1989)	w × r^0.10	117.5 kg	1–8 reps (overshoots >8)
O'Conner (1989)	w × (1 + 0.025r)	112.5 kg	1–10 reps

Fuente: Mayhew et al. (1992) / Reynolds et al. (2006) vía PubMed; fórmulas y resultados verificados contra el contenido de la calculadora.

How it works

The Math — Epley, Brzycki, Lombardi Compared

All three formulas take the same two inputs (weight on the bar, reps completed at or near failure) and predict a 1-rep max. They disagree most at high reps:

Epley   (1985):  1RM = w × (1 + r/30)
Brzycki (1993):  1RM = w × 36 / (37 − r)
Lombardi(1989):  1RM = w × r^0.10
O'Conner(1989):  1RM = w × (1 + 0.025r)

Worked example — 100 kg × 5 reps:

Epley   : 100 × (1 + 5/30)    = 100 × 1.167 = 116.7 kg
Brzycki : 100 × 36/(37 − 5)  = 100 × 1.125 = 112.5 kg
Lombardi: 100 × 5^0.10        = 100 × 1.175 = 117.5 kg
O'Conner: 100 × (1 + 0.125)  = 100 × 1.125 = 112.5 kg

The spread (~5 kg) is normal. For 3–5 rep sets the formulas converge within 2–3%. Above 8 reps, Lombardi overshoots by 5–10% and Brzycki tends to be more accurate.

Common Squat Weights by Rep Count (100 kg 1RM)

Use this reference table if your 1RM is near 100 kg. Scale proportionally.

Reps	Epley 1RM	% of 1RM	Training goal
1	100 kg	100%	Max single / competition
2	106.7 kg	95%	Peaking, heavy doubles
3	110 kg	92.5%	Strength triples
5	116.7 kg	85%	Strength 5/3/1 top set
6	120 kg	83%	Strength-hypertrophy crossover
8	126.7 kg	79%	Hypertrophy working sets
10	133.3 kg	75%	Volume hypertrophy
12	140 kg	71%	High-rep hypertrophy

%1RM / Reps Reference Table

Useful for plugging into 5/3/1, Sheiko, Conjugate, or any percentage-based template:

% of 1RM	RPE	Typical Reps	Use
100%	RPE 10 — true max	1	Competition / test
95%	RPE 9	2	Peaking singles
90%	RPE 8	3–4	Heavy strength
85%	RPE 7	5–6	5/3/1 top sets
80%	RPE 6.5	6–8	Strength-hypertrophy
75%	RPE 6	8–10	Volume / hypertrophy
70%	RPE 5	10–12	Hypertrophy block
65%	RPE 4	12–15	Endurance / warm-up

Squat Strength Standards (back squat, kg, by training level)

Level	70 kg BW	80 kg BW	90 kg BW
Beginner	60–80 kg	70–95 kg	80–105 kg
Novice	80–100 kg	95–115 kg	105–130 kg
Intermediate	100–130 kg	115–145 kg	130–165 kg
Advanced	150–185 kg	175–210 kg	195–235 kg
Elite (competitive)	200+ kg	230+ kg	260+ kg

(Source: ExRx.net, Stronger by Science, StrengthLevel)

Bar Position Changes The Number

A high-bar (Olympic) squat and a low-bar (powerlifting) squat produce different 1RMs from the same athlete:

Low-bar 1RM is 5–12% higher than high-bar 1RM (Stronger by Science survey data)

If you train high-bar but compete USAPL/USPA, multiply your estimated high-bar 1RM by ~1.08 for a rough low-bar target

A 500 lb low-bar competitor probably high-bars 445–475 lb on a good day

Depth Standards

Standard	Definition	Where
Parallel	Top of knee level with hip crease	USAPL, USPA, IPF
Full depth (ATG)	Hip well below knee, hamstrings on calves	Olympic weightlifting, CrossFit
High squat	Hip above knee	Gym only — red-lighted in meets

Programming Your 1RM Number

Wendler 5/3/1: runs every cycle off a Training Max (TM) = 85–90% of estimated 1RM. Week 3 top set is 95% TM × 1+ AMRAP. You re-estimate 1RM each cycle from that AMRAP.

Sheiko #29/#32: squat days run at 70–85% 1RM for sets of 2–5 reps. Total reps per session at >70% can exceed 30 — accurate 1RM matters a lot.

Bulgarian method: requires a daily heavy single. Back-off sets run at 85–90% of the day's top single.

Smolov base cycle: 4 squat sessions/week, percentages built off a fresh 1RM. Plug a stale or inflated 1RM into Smolov and you'll quit by Week 2.

Common Errors

1. AMRAP wasn't actually AMRAP. If you stop a top set with 2–3 reps in reserve, Epley underpredicts your max. Push the set to where the next rep would have failed.

2. No spotter or safeties. Set the safeties at the bottom of your squat, use a power rack. If neither is available, cap the test at 5RM and trust the math.

3. High-rep test sets. Epley is most accurate at 1–6 reps. Above 10 reps, the formula overshoots by 10–15%.

4. Comparing across gear/bar position. A belted, sleeved low-bar squat can be 10–20 kg above an unbelted high-bar single. Tag your inputs with the gear used.

5. Testing too close to a meet. Don't test a true 1RM in the last 14 days before competition. Use a 3RM or 5RM at 4–6 weeks out.

Worked Example

You lifted 100 kg for 5 reps

1RM = 100 × (1 + 5/30) = 100 × 1.1667

Estimated 1RM = 116.7 kg

~117 kg 1RM

Frequently asked questions

What's the Epley formula for 1RM and how accurate is it?

Epley (1985): 1RM = Weight × (1 + Reps ÷ 30). At 3–6 reps the formula is typically within ±2–5% of a true max. Above 10 reps accuracy drops to ±10–15%. The Epley equation is used in virtually every strength program (5/3/1, Sheiko, Smolov) as the de facto standard for estimating 1RM from submaximal sets.

What's a strong back squat for a 200 lb man?

Going by ExRx and Symmetric Strength standards at 200 lb bodyweight: novice ~230 lb, intermediate ~315 lb, advanced ~405 lb, elite/competitive ~500 lb+. A 1.5× bodyweight squat (300 lb) is the common recreational lifter marker; 2× bodyweight (405 lb) is the threshold most competitive lifters aim to cross.

What's a strong squat for a woman at 145 lb bodyweight?

Strength standard bands: novice ~125 lb, intermediate ~175 lb, advanced ~235 lb, elite ~290 lb. A 2× bodyweight squat (290 lb) at 145 lb places a female lifter very competitively at USAPL 63–69 kg meets.

How often should I squat — once, twice, or more per week?

Depends on the program: Wendler 5/3/1 runs once a week heavy plus an optional lighter day. Texas Method uses 3× per week (volume Monday, light Wednesday, intensity Friday). Sheiko runs 2–3 squat sessions/week. For most intermediate lifters, 2 sessions/week (one heavy, one volume) hits the sweet spot without compromising recovery.

Why does my calculated 1RM feel too high when I actually try it?

Three usual culprits: (1) the test set wasn't true AMRAP — you left reps on the bar, so Epley overprojects; (2) you tried the 1RM cold or after fatigue; (3) bar position changed — you tested high-bar in training but tried a low-bar single. Recompute from a fresh 3RM, fully warm up (45–60 min), and match bar position.

What's the typical high-bar to low-bar squat ratio?

Most trained lifters move 5–12% more weight low-bar than high-bar. A 405 lb high-bar squat usually translates to about 425–455 lb low-bar once technique is dialed in. The gap is larger for taller lifters with long femurs.

Should I test a true 1RM or trust the calculator?

For 90% of lifters in 90% of training blocks: trust the calculator. A true 1RM eats 7–10 days of recovery, needs a 45–60 min warm-up, and carries real injury risk. Reserve direct 1RM testing for competition day or once every 8–12 weeks. Use 3RM or 5RM retests every 4 weeks — that's what 5/3/1 and Juggernaut are built around.

How long does it take to recover after a max squat test?

Plan on 5–10 days of reduced volume and intensity after a true 1RM squat. Days 1–3: mobility work, very light bike. Days 4–6: 50–65% bar work, no AMRAPs. Day 7+: ramp back to 75–85% working sets. Even elite lifters (Ed Coan, Kirk Karwoski training logs) show ~10 days of dialed-back volume after meet-day attempts.

Does the calculator work for paused squats and tempo squats?

The math is the same but the inputs aren't comparable. A 3-second paused squat at 100 kg × 5 reps doesn't predict the same 1RM as touch-and-go 100 kg × 5 reps — your paused 1RM is typically 5–8% lower than competition 1RM. Use paused-set data only when projecting paused competition attempts; mixing rep schemes contaminates the estimate.

What if I'm a beginner and don't know my top set?

Don't test a 1RM. Run Starting Strength or StrongLifts 5×5 for 12 weeks and let linear progression reveal your 5RM. Once you stall on linear progression (usually around bodyweight × 1.2–1.5 squat), plug the last successful 5×5 set into the calculator — that gives a reliable estimated 1RM to build the next program on.

Sources & references

Methodology & trust

Editorial

Sports calculator with its formula verified automatically against NSCA — Testing Maximum Strength (Essentials of Strength Training and Conditioning), per our editorial policy and methodology.

Updates

Updated: June 2026. Parameters are verified periodically against the cited sources.

Privacy

Calculations run 100% in your browser. We do not store or transmit your data.

Limitations

Indicative results. For critical decisions, consult a professional.

📌 How to cite this calculator

Rodríguez, M. (2026). 1RM Back Squat Calculator — Estimate Your Max (Epley Formula). Hacé Cuentas. https://hacecuentas.com/en/1rm-squat-estimator

Content licensed under CC-BY 4.0 — reuse it citing the source with a link to Hacé Cuentas.

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