Squat calculator

How your squat 1RM is calculated

The calculator turns a submaximal squat set into an estimated one rep max using a prediction formula, so you do not have to work up to a true single to get a usable number.

It uses the load-rep relationship: the more reps you get at a given weight, the further below your true max that weight sits, in a fairly consistent curve. Feed in the weight and reps from a hard set, and the formula projects where that curve would hit a single rep.

Worked example, Epley

You squat 140 kg for 5 reps and use Epley, the default formula: 140 × (1 + 5 ÷ 30) = 140 × 1.167 = 163.3 kg estimated 1RM. Try 3 reps instead of 5 at the same weight and the estimate drops, because a set of 3 sits closer to your actual max than a set of 5 does.

Push the same 140 kg out to 8 reps instead and Epley returns 140 × (1 + 8 ÷ 30) = 177.3 kg, roughly 14 kg higher than the 5 rep estimate for three extra reps. That gap is the reason a hard set of 3 to 6 is the sweet spot for this calculator: it is heavy enough to closely resemble a true single, but light enough that fatigue has not started to distort your depth or bar speed by the last rep. An 8 or 10 rep squat set can still be fed in, but treat the resulting number as a rough ceiling rather than a figure to load precise training percentages from.

Why the squat needs a caveat the bench press does not

The squat recruits more total muscle mass than the bench press and depends more on bracing, positioning and confidence under a heavy bar. Two lifters with identical strength can grind out a very different number of reps at the same percentage depending on technical efficiency, which is one reason squat estimates carry a wider margin than bench press estimates from the same formula.

Reps in reserve and RPE

The formulas assume the input set stopped a rep or two short of failure, roughly RPE 8 or 9 in coaching shorthand. On the squat that line is harder to judge than on the bench press, because a set can end for several different reasons: legs failing, the brace giving out, or a loss of confidence under a heavy bar rather than strength actually running out. A set stopped early because it felt heavy but technique stayed clean and depth held throughout gives the formula good information to work from. A set that ground on well after depth and bar speed started to break down should be logged with that in mind, since the extra reps came from technique compensating for fatigue rather than from genuine reps still in reserve.

If you are not sure whether the input set was a clean RPE 8 or a true grind, treat the resulting estimate as the upper end of a range rather than a fixed figure, and confirm it the next time you squat with a set you are more confident about.

Which formula to use for the squat

The calculator gives you five formulas: Epley, Brzycki, Lombardi, Wathan and O'Conner. LeSuer and colleagues tested all five against real tested 1RMs in the squat in 1997, and found strong correlations with actual performance across the group, though individual squat estimates spread further from the tested number than bench press estimates from the same formulas.

Epley (default)

Weight × (1 + reps ÷ 30). The familiar default and a reasonable middle ground, though LeSuer et al. found every equation except Wathan differed significantly from a tested squat max. Wathan was the only equation they found accurate for this lift, so cross-check with it before setting a training max.

Brzycki

Weight × 36 ÷ (37 minus reps). More conservative than Epley up to about 10 reps, which suits a lift where estimates already run wider than usual, but its denominator collapses past that point and overtakes every other formula on this page, so keep it away from a high rep squat AMRAP.

Lombardi and Wathan

Lombardi (weight × reps to the power of 0.10) sits a touch higher than Epley below about 6 reps and crosses below it above that, giving the most conservative of the five estimates at 11 to 12 reps. Wathan uses an exponential curve and agrees closely with Epley in the 3 to 8 rep range, which covers most squat programming.

O'Conner

Weight × (1 + 0.025 × reps). The most conservative of the five from about 6 to 10 reps, a reasonable choice if you would rather set a training max on the low side for a new squat programme.

Because the squat is technically demanding, cross-check with a second formula whenever the input set felt like a grind rather than a clean, fast set.

Why the five formulas disagree

Run the same 140 kg set through all five formulas and the gap between them widens with reps, in both absolute and percentage terms. At 3 reps, Brzycki gives 148.2 kg and Lombardi gives 156.3 kg, a spread of about 8 kg, roughly 5 percent. At 6 reps the range runs from O'Conner's 161 kg to Wathan's 168.5 kg, still around 5 percent. By 10 reps it opens up to about 14 kg, from O'Conner's 175 kg to Wathan's 188.6 kg, close to 8 percent of the estimate.

That widening spread is the squat's version of a pattern every lift on this page shows: the further the input set sits from a true single, the more the five curves disagree about where that single would have landed, because each is extrapolating further from the same starting point. Running two or three formulas and looking at how tightly they cluster tells you more about how far to trust the number than any single formula does on its own.

Squat percentages at a glance

Once you have an estimated max, this is the loading range squat programmes actually live in. The table assumes a 140 kg estimated 1RM; the calculator above works from your own number.

Squat technique standards

A number only means something if the reps behind it were legitimate. These are the standards most coaches and federations judge a squat against.

Depth

The standard for a valid squat, used in powerlifting judging, is the hip crease dropping below the top of the knee at the bottom of the rep. Squatting to depth recruits more of the hip and glute musculature through a fuller range of motion than a partial squat, which is part of why depth affects both the training stimulus and the number you should trust from a set.

High bar or low bar

A high bar position, with the bar sitting on the upper traps, keeps the torso more upright and shifts more load onto the quads. A low bar position, sitting across the rear delts, allows a greater forward lean and shifts more work to the hips and posterior chain, which usually lets lifters move more total weight. Neither is wrong; pick the one that matches your goal and stay consistent between test sets so your estimates are comparable over time.

Bracing and stance

A big breath and a hard brace through the midsection before descending keeps the spine stable under load. Stance width is individual, generally just outside shoulder width with toes turned out slightly, and should let the knees track in line with the toes throughout the rep rather than caving inward.

Footwear and set-up

A flat, hard sole or a dedicated weightlifting shoe with a raised heel gives a more stable base than a cushioned running shoe, which can compress unevenly under a heavy bar and shift your balance mid-rep. Keep your footwear consistent between the sessions you use to estimate or test your max, since a change here can move the number on its own.

Squat strength standards by body weight

Strength standards let you see how your squat compares to other lifters at your body weight, though they are approximate and vary depending on which dataset compiled them. The figures below are drawn from Strength Level, which aggregates millions of user-submitted lifts, and are broadly in line with the categories Symmetric Strength uses from competition data (both cited in Sources below). Treat them as a compass, not a target: age, training age, limb length and squat style all move the number.

How to use your squat max

Once you have an estimated max, set a training max around 90 to 95 percent of it and build your working sets off that number instead of the raw estimate. It leaves room to progress across a block instead of starting at the ceiling. If your five formulas spread wide when you ran the numbers, lean toward the lower end of that 90 to 95 percent range rather than the top.

Programming around the squat

Strength blocks usually spend most of their working sets at 75 to 90 percent for 3 to 6 reps, with heavier singles and doubles reserved for peaking phases close to a test or competition. Hypertrophy-focused blocks sit lower, around 65 to 80 percent, for higher volume across more sets.

Retesting

Recalculate every 4 to 8 weeks from a fresh hard set rather than trusting an old number. The squat responds well to consistent training, so a number that felt accurate two months ago is often a few kilograms light by the time you retest.

Accessory work that moves this number

A squat 1RM does not move on squat days alone. Front squats and pause squats out of the hole build the positional strength and confidence that let you actually use the raw leg strength you have, which is often what separates a tested max from an estimate that looked good on paper. Leg press and hack squat work add quad volume without the technical demand of a heavy back squat, useful for lifters who can add strength faster than they can add confidence under a bar.

Hip thrusts and Romanian deadlifts target the glutes and hamstrings that drive the bar out of the bottom, particularly on a low bar squat where the hips do more of the work. None of these lifts show up in the calculator, but a training block that neglects them for months at a time often shows up as a squat estimate that stalls even while the input sets keep climbing at the same rate, a sign the bottleneck has moved away from the main lift itself.

Common squat mistakes

Not hitting depth on the input set. A high, partial squat lets you move more weight for the same reps, which inflates the estimate compared with a squat judged to standard depth.

Knees caving inward under load. Beyond the injury risk, it usually signals the set was heavier than the input reps suggest and the lifter compensated with position rather than strength.

Losing the brace mid-set. A collapsing brace changes bar speed and rep quality on the later reps of a set, which skews what the formula assumes about effort.

Heels rising off the floor. Often a mobility issue rather than a strength one, and it changes the mechanics of the lift enough that the rep does not represent the same movement pattern the formula was validated on.

Testing depth and bar position inconsistently between sessions. Switching from high bar to low bar, or letting depth drift, makes it impossible to tell whether a change in your estimated max is real progress or a different exercise.

Rushing the descent. Dropping into the bottom position too fast makes it harder to control the rep and hold depth, and often costs more strength through the sticking point than a controlled, deliberate descent would.

How coaches use a squat calculator

For a coach, a squat calculator turns one logged set into a full week of percentages without recalculating everything by hand for every client on a different number.

A practical routine: have clients log a hard triple or set of 5 on the squat every 4 to 6 weeks, recalculate the estimated max, and let the block's working percentages update from the new number automatically.

Scraler's workout builder does this for you: set percentages on a template once, and each client's squat working weight recalculates from their own logged numbers instead of you rebuilding the plan by hand. See workout programming.