1RM Calculator for Bench Press, Squat and Deadlift
Estimate your one-rep max below from the load and repetitions in a set you already completed. This calculator for adults compares Brzycki-style and Epley estimates in kilograms or pounds for bench press, squat and deadlift. The result is a prediction, not a measured maximum or an exact safe training load.
1RM calculator
Use a recent set you already completed with controlled, consistent technique. These formulas estimate performance from load and repetitions; they do not measure your maximum or tell you what is safe to lift. A set stopped far short of its repetition limit can underestimate capacity. You do not need to perform a new maximal attempt or train to uncontrolled failure to use this page.
Runs on this page. Inputs are not sent or saved.
Controls become available after the page finishes loading. If they stay disabled, use the equations and example below.
Formula differences are not a confidence interval. Results vary with technique, exercise and the individual. Keep the same lift variation and equation when comparing sessions. If pain, an injury or a health condition affects exercise, get individual guidance. This is general educational information, not a youth-testing or rehabilitation plan.
Equations and worked example
For 2–10 repetitions: Brzycki-style = load × 36 ÷ (37 − repetitions). Epley = load × (1 + repetitions ÷ 30). No averaging or winner is implied.
At 120 lb × 8: Brzycki = 148.97 lb before one-decimal display rounding; Epley = 152.00 lb.
These are conventional normalized equations, not bit-for-bit copies of the rounded coefficients printed in LeSuer et al. (1997), Table 1, or a verified implementation of the Setgraph app. Rounding affects display only. Estimates use matching units and remain invariant when units change.
How to Use the 1RM Calculator
Select bench press, squat or deadlift, then choose kg or lb. The lift selection names the result; all three use the same equations.
Enter the total load, including the bar, plates and any collars you counted. Use a decimal point and select 1–10 completed repetitions.
Choose Calculate estimate. For 2–10 reps, you will see both estimates. For one rep, the tool records the single and explains that your maximum is unknown.
Use Clear to start again, or Use example to fill the worked example before calculating. If you edit the load, reps or lift, calculate again. Switching units converts the existing values rather than treating the same number as a different load.
Use a recent set performed with controlled, consistent technique. A set stopped far short of its repetition limit can underestimate capacity because the equations do not know how many reps you had left. You do not need a new maximal attempt or an uncontrolled failure set to use this page.
What Is a 1RM, and What Does This Tool Estimate?
A one-rep max (1RM) is the greatest load you can complete for one repetition under a defined lifting standard. An estimated 1RM is calculated from a different performance, so keep it separate from a measured maximum in your training log.
For 2–10 repetitions, the calculator uses these exact equations, with load and result in the same units:
Brzycki-style: estimated 1RM = load × 36 ÷ (37 − repetitions)
Epley: estimated 1RM = load × (1 + repetitions ÷ 30)
A recorded single is not automatically a maximum. The tool therefore does not extrapolate a one-rep input or label it an estimated 1RM. The supported rep range is a tool limit, not a guarantee that every estimate within it is accurate.
Worked Example: 120 lb for 8 Repetitions
Brzycki-style: 120 × 36 ÷ (37 − 8) = 148.9655… lb, displayed as 149.0 lb. Epley: 120 × (1 + 8 ÷ 30) = 152.0 lb. The 148.97 lb shown in the app screenshot below matches this Brzycki-style result rounded to two decimals.
For a percentage example, 70% of the unrounded Brzycki-style estimate is about 104.3 lb. That is arithmetic, not a prescribed training load or a promise that you can complete a particular number of reps. The web calculator shows the two estimates; the app’s percentage and XRM tables are described separately below.
How Accurate Are Rep-Based Estimates?
LeSuer and colleagues’ 1997 comparison enrolled 67 untrained college students and examined seven equations using sets of ten or fewer repetitions; the number completing each lift varied. Mean prediction error differed by lift, and all seven equations underestimated deadlift 1RM on average in that sample. The study does not establish a universally best equation for every lifter or movement.
The equations implemented here use conventional normalized coefficients. LeSuer’s Table 1 prints rounded decimal coefficients, so this tool is not a bit-for-bit reproduction of that table or a verified copy of the Setgraph app’s calculation. Differences between formulas are not confidence intervals, and averaging them would not prove a more accurate maximum.
Keep each comparison consistent:
Squat: record the variation and repeatable depth.
Bench press: distinguish paused and touch-and-go repetitions.
Deadlift: distinguish dead-stop and touch-and-go repetitions.
Changing technique, equipment or range of motion can change what the number represents. For a separate, limited bench comparison, use the bench press calculator with adult competition medians.
Using Setgraph’s In-App 1RM Feature
The Setgraph 1RM feature page describes entering a set’s load and repetitions, choosing an equation from its Formula menu, and viewing percentage and XRM tables. The screenshots below document app screens, not the web calculator. Labels and access can vary by app version and platform, and these images do not verify current entitlement.
The estimate screen shows 120 lb for eight reps and an Apply 1RM Estimate control. Its maximum-effort wording should not be read as an instruction to perform a new failure set for this article.
Percentage Tables
The percentage screen shows 70% as 104.3 lb. A percentage is one reference for planning; choose actual training loads according to your program, completed repetitions, technique and effort rather than treating the table as a safety check.
Updating a Recorded Single
The feature page describes tapping Set 1RM after recording a one-rep set above the current best. The screenshot uses the older label Update 1RM. Both describe a user action; neither establishes that every metric updates without your input.
XRM Estimates
The app’s XRM table estimates a load for a chosen repetition count. It does not guarantee that load for repeated sets or prescribe a workout. Keep the prediction separate from the load and reps you actually complete.
Frequently Asked Questions
How many reps should I use?
The calculator accepts 1–10 completed repetitions. It estimates 1RM from 2–10 reps and treats one rep as a recorded single with maximum unknown. Use an existing controlled set; a lower rep count does not guarantee accuracy.
How do you calculate 1RM?
For 2–10 reps, the web calculator shows Brzycki-style: load × 36 ÷ (37 − reps), and Epley: load × (1 + reps ÷ 30). Use one load unit. The lift selector labels the result; it does not change the equation.
Which formula is most accurate?
No equation is universally most accurate across lifts and people. Comparing two outputs shows their difference, not a confidence interval, a verified maximum or a guaranteed safe load.
Why do my squat, bench and deadlift estimates differ?
They describe different lifts and sets. Compare each lift with its own previous results using consistent technique, range of motion, units and equation.
Can I use this web calculator without the app?
Yes. The calculator runs on this page and needs JavaScript for its controls. The equations and worked example remain in the article if the controls are unavailable. It does not update your Setgraph records.
Is every in-app 1RM feature free?
App features and access terms are separate from this web calculator. Check the current app and store terms for your platform and account; these screenshots do not establish universal free or unlimited access.
When should I update an estimate?
Recalculate from a newer comparable set when that helps you review progress. Keep the equation and lifting technique consistent, and retain the original load and repetitions alongside the estimate.
Can an estimate replace a true max test?
An estimate may be enough to follow training trends when a maximal test is unnecessary. It cannot confirm that you can lift the predicted weight once or that attempting it would be safe.
Keep the Estimate in Context
This tool is for adults and provides general educational information. It is not a youth-testing or rehabilitation plan. If pain, an injury or a health condition affects exercise, seek individual guidance before using an estimate to make training decisions.
For the next step, read about progressive overload or 1RM testing context. To review the current app options, visit Setgraph’s 1RM feature or open Setgraph. The web calculator does not change your app records.
