Your one-rep max (1RM) is the heaviest load you could lift once for a given exercise with solid technique. You rarely need to test it under a true maximal single. For most gym programming, a formula estimate from a hard submaximal set is safer and repeatable enough.
This guide walks through the two formulas used on our One-Rep Max Calculator — Epley and Brzycki — and how to use the result with plate loading and RPE.
Why estimate instead of testing a true max
A true 1RM attempt needs a long warm-up, fresh recovery, and a readiness to miss. Estimates are useful when you want:
- Working weights as a percentage of 1RM
- Progress checks without peaking every cycle
- A shared reference for programs written in %1RM
Treat every estimate as a training number, not a competition total. Formulas are population averages; individual day-to-day strength varies.
Step 1: Choose a clean submaximal set
- Warm up with light ramping sets on the same lift.
- Pick a weight you can lift for about 3–8 reps with the same technique you use in training.
- Stop near failure — roughly 0–1 reps left — while keeping form intact. If technique breaks, stop the set and use the last clean rep count.
- Record weight, reps completed, and the exercise (for example bench press, squat, or deadlift).
Sets much longer than about 10–12 reps are a poor fit for 1RM formulas. At that point muscular endurance starts to dominate the result.
Step 2: Apply Epley and Brzycki
With weight w and reps r (where r is greater than 1):
- Epley:
1RM = w × (1 + r / 30) - Brzycki:
1RM = w × (36 / (37 − r))
If you completed a true single (r = 1), the estimate is simply the weight lifted.
Worked example
You squat 100 kg for 5 clean reps near failure.
| Formula | Calculation | Estimate |
|---|---|---|
| Epley | 100 × (1 + 5/30) |
116.7 kg |
| Brzycki | 100 × (36 / 32) |
112.5 kg |
| Average | midpoint of the two | 114.6 kg |
Our calculator shows all three so you can see the spread. When they disagree by more than a small margin, re-check that the set was actually close to failure and within the 2–10 rep range.
Step 3: Round to a loadable weight
Round the estimate to the nearest plate jump you can load — often 2.5 kg or 5 lb. False precision (for example 231.4 lb) does not make the estimate more accurate.
Use the Plate Loading Calculator to convert a target barbell weight into plates per side for kg or lb inventories. For the formula, bar presets, and a worked example, see How to Load a Barbell.
Step 4: Turn 1RM into training loads
Common starting zones (approximate):
| Goal | Typical intensity |
|---|---|
| Technique / recovery work | ~50–65% of 1RM |
| Hypertrophy-style sets | ~65–80% of 1RM |
| Strength-focused sets | ~80–90% of 1RM |
| Heavy singles / doubles | ~90%+ of 1RM |
These are starting points, not prescriptions. How many reps you can do at a given percentage also depends on the lift, fatigue, and how the set feels.
Using RPE when the set was not quite to failure
If you stopped with reps in reserve, a percentage chart based on reps × RPE can be a better bridge than pretending the set was a max-effort set. Our RPE & Rest Calculator maps common reps × RPE combinations to an approximate %1RM, and can estimate an e1RM or a target load from a known 1RM.
A simple RIR helper used there is RIR ≈ 10 − RPE (for example RPE 8 ≈ 2 reps in reserve). For choosing working-set loads and mid-session adjustments, see How to Use RPE for Working Sets. If the estimated working weight wrecks form on set one, treat it as too heavy — How to Know if a Weight Is Too Heavy.
Limitations to keep in mind
- Formulas drift as reps climb past roughly 10–12.
- Machines, isolation lifts, and very slow tempos may not match free-weight research averages.
- Poor sleep, stress, or a hard training week can move your “true” max without the formula knowing.
- Never chase a formula number through broken technique.
Put it to work on real lifts
Estimate 1RM on the lifts you actually train, then open the matching exercise guide for setup and range-of-motion cues:
For a fuller pressing shortlist around the bench, see Best Chest Exercises for Strength and Muscle. Choosing bar vs dumbbells for that main press? See Barbell vs Dumbbell Bench Press. For rows, pull-ups, and deadlift accessories, see Best Back Exercises for Strength and Muscle. For overhead presses and delt isolation, see Best Shoulder Exercises for Strength and Muscle. For squats, leg presses, and hinges, see Best Leg Exercises for Strength and Muscle. To place those lifts into a weekly template, see Full-Body Training Split Explained, Upper/Lower Split Explained, or Push/Pull/Legs Split Explained. Prefer a fixed barbell A/B? See 5x5 for Beginners. Building sessions around dumbbells instead of a competition barbell? See Best Dumbbell Exercises for Strength and Muscle. For a barbell compound shortlist, see Best Barbell Exercises for Strength and Muscle. For a no-equipment full-body shortlist, see Best Bodyweight Exercises for Strength and Muscle. For constant-tension cable accessories, see Best Cable Exercises for Strength and Muscle. Prefer a guided bar path when free racks are busy? See Best Smith Machine Exercises for Strength and Muscle. Prefer selectorized machines? See Best Leverage Machine Exercises for Strength and Muscle. Prefer straps for portable angle-based training? See Best Suspension Exercises for Strength and Muscle. Prefer sled presses, hacks, pushes, and drags? See Best Sled Exercises for Strength and Conditioning. Prefer medicine-ball slams, wall balls, throws, and core work? See Best Medicine Ball Exercises for Power and Conditioning. Training with bands instead of a loaded barbell? See Best Resistance Band Exercises for Full-Body Training — band tension does not map cleanly to 1RM formulas. Prefer a kettlebell for conditioning and full-body sessions? See Best Kettlebell Exercises for Strength and Conditioning.
When your working sets get easier at the same RPE, re-run the estimate and update your percentages — see Progressive Overload for Beginners for load/rep progression rules.
New to library pages? See How to Read Exercise Instructions on This Site.
Quick links
- Warm-Up Sets vs Working Sets
- How to Choose a Training Split — pick full-body vs upper/lower vs PPL by gym days
- One-Rep Max Calculator — Epley, Brzycki, and training percentages
- RPE & Rest Calculator — reps × RPE → %1RM and rest ranges
- Plate Loading Calculator — load the bar to your target
- How to Load a Barbell — plate math, inventories, and loading habits
- Progressive Overload for Beginners — load, reps, and double progression
- How to Know if a Weight Is Too Heavy — when a %1RM pick is too much for clean reps
- How to Break a Lifting Plateau — when estimated working loads stop moving for weeks
- What to Track in a Workout Log — log the hard sets you use for e1RM estimates
- How to Warm Up Before Lifting — RAMP outline before heavy sets
- How to Deload for Strength Training — lighter weeks when fatigue stacks up
- How Long to Rest Between Sets — rest ranges for heavy working sets
- How Many Sets and Reps Should You Do — turn %1RM into set/rep schemes
- How Many Days a Week Should You Lift — schedule training days around your plan
- How Much Protein Do You Need — bodyweight × g/kg targets with the protein calculator
- How to Calculate BMI — WHO kg/m² formula, categories, and lifter caveats
- How to Calculate Body Fat with the Navy Method — U.S. Navy circumference estimate and measurement tips
- Best Chest Exercises — presses, dips, flies, and a simple session template
- Best Back Exercises — pull-ups, rows, pulldowns, and a simple session template
- Best Leg Exercises — squats, presses, hinges, lunges, and a simple session template
- Best Shoulder Exercises — overhead presses, raises, rear-delt work, and a simple session template
- Best Arm Exercises — curls, triceps presses/extensions, and a simple finisher template
- Best Core Exercises — planks, Pallof presses, raises, and a simple finisher template
- Barbell vs Dumbbell Bench Press — which flat press to prioritize for strength vs joint comfort
- How to Increase Your Bench Press — turn 1RM estimates into a 2×/week bench plan with accessories
- How to Increase Your Squat — turn 1RM estimates into a 2×/week squat plan with accessories
- How to Increase Your Deadlift — frequency, progressive overload, and pause/deficit accessories around a main floor pull
- How to Increase Your Sumo Deadlift — frequency, progressive overload, and pause/block accessories around a main wide-stance floor pull
- How to Increase Your Trap Bar Deadlift — frequency, progressive overload, and pause/deficit accessories around a main hex-bar floor pull
- How to Increase Your Kettlebell Swing — frequency, progressive overload, and crisp hip-snap practice around a main ballistic kettlebell swing
- How to Increase Your Overhead Press — frequency, progressive overload, and pause/push-press accessories around a main vertical press
- How to Increase Your Pull-Ups — frequency, progressive overload, and assistance/negatives/weighted work around a main vertical pull
- How to Increase Your Chin-Ups — frequency, progressive overload, and assistance/negatives/weighted work around a main underhand chin-up
- How to Increase Your Hanging Leg Raises — frequency, progressive overload, and knee→straight→weighted work around a main hanging leg raise
- How to Increase Your Lying Leg Raises — frequency, progressive overload, and quiet floor-flexion practice around a main lying leg raise
- How to Increase Your Toes to Bar — frequency, progressive overload, and quiet hang-to-bar practice around a main toes-to-bar
- How to Increase Your Plank — frequency, progressive overload, and quiet anti-extension practice around a main plank
- How to Increase Your Mountain Climber — frequency, progressive overload, and quiet plank knee-drive practice around a main mountain climber
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- How to Increase Your Sit-Ups — frequency, progressive overload, and quiet longer-range floor-flexion practice around a main sit-up
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- How to Increase Your Rows — frequency, progressive overload, and supported/pause accessories around a main horizontal row
- How to Increase Your Seated Cable Row — frequency, progressive overload, and pause/tempo accessories around a main seated cable row
- How to Increase Your Dips — frequency, progressive overload, and assistance/negatives/weighted work around a main dip
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- How to Increase Your Hip Thrust — frequency, progressive overload, and pause/single-leg accessories around a main hip thrust
- How to Increase Your Hip Abduction — frequency, progressive overload, and quiet-peak practice around a main lateral hip abduction
- How to Increase Your Hip Adduction — frequency, progressive overload, and quiet-peak practice around a main medial hip adduction
- How to Increase Your Inverted Row — frequency, progressive overload, and angle/pause/tempo practice around a main bodyweight inverted row
- How to Increase Your T-Bar Row — frequency, progressive overload, and pause/tempo practice around a main machine T-bar row
- How to Increase Your Thruster — frequency, progressive overload, and quiet squat-to-press practice around a main thruster
- How to Increase Your Push Press — frequency, progressive overload, and quiet dip-drive practice around a main push press
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- How to Increase Your Rear Delt Fly — frequency, progressive overload, and pause/tempo accessories around a main rear-delt fly / reverse fly
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- How to Increase Your Arnold Press — frequency, progressive overload, and pause/tempo accessories around a main Arnold press
- How to Increase Your Bicep Curl — frequency, progressive overload, and pause/tempo accessories around a main bicep curl
- How to Increase Your Preacher Curl — frequency, progressive overload, and stretch/tempo work around a main preacher curl
- How to Increase Your Incline Curl — frequency, progressive overload, and stretch/tempo work around a main incline curl
- How to Increase Your Concentration Curl — frequency, progressive overload, and pause/tempo work around a main concentration curl
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- How to Increase Your Zottman Curl — frequency, progressive overload, and pause/tempo work around a main Zottman curl
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- How to Increase Your Tricep Kickback — frequency, progressive overload, and pause/tempo accessories around a main tricep kickback
- How to Increase Your Skull Crusher — frequency, progressive overload, and pause/tempo work around a main skull crusher
- How to Increase Your Close-Grip Bench Press — frequency, progressive overload, and pause/lockout accessories around a main close-grip press
- How to Increase Your Incline Bench Press — frequency, progressive overload, and pause/tempo accessories around a main incline press
- How to Increase Your Decline Bench Press — frequency, progressive overload, and pause/tempo accessories around a main decline press
- How to Increase Your Floor Press — frequency, progressive overload, and pause/tempo accessories around a main floor press
- How to Increase Your Chest Fly — frequency, progressive overload, and pause/tempo accessories around a main chest fly
- How to Increase Your Pullover — frequency, progressive overload, and pause/tempo accessories around a main pullover
- How to Increase Your Straight Arm Pulldown — frequency, progressive overload, and pause/tempo accessories around a main straight-arm pulldown
- How to Increase Your Lunges — frequency, progressive overload, and reverse/Bulgarian/step-up accessories around a main lunge pattern
- How to Increase Your Leg Press — frequency, progressive overload, and hack/single-leg accessories around a main machine press
- How to Increase Your Hack Squat — frequency, progressive overload, and foot-placement/single-leg accessories around a main hack squat
- How to Increase Your Bulgarian Split Squat — frequency, progressive overload, and rear-foot/front-foot accessories around a main Bulgarian split squat
- How to Increase Your Step-Up — frequency, progressive overload, and box-height/load accessories around a main step-up
- How to Increase Your Calf Raise — frequency, progressive overload, and standing/seated accessories around a main calf raise
- How to Increase Your Leg Curl — frequency, progressive overload, and lying/seated/single-leg accessories around a main machine curl
- How to Increase Your Leg Extension — frequency, progressive overload, and seated/single-leg accessories around a main machine extension
- Push/Pull/Legs Split Explained — sample push, pull, and legs days plus 3- vs 6-day schedules
- Full-Body Training Split Explained — 2–3 day A/B/C pattern template
- Upper/Lower Split Explained — 4-day Upper A/B and Lower A/B template
- 5x5 for Beginners — A/B full-body template with squat, bench, row, press, and deadlift
- Best Resistance Band Exercises — full-body band shortlist when free weights are unavailable
- Best Kettlebell Exercises — hinge, squat, press, pull, and carry shortlist
- Best Dumbbell Exercises — press, pull, squat, hinge, and carry shortlist
- Best Barbell Exercises — squat, hinge, press, and pull shortlist
- Best Bodyweight Exercises
- Best Cable Exercises — push, pull, squat, hinge, and core shortlist
- Best Smith Machine Exercises
- Best Leverage Machine Exercises — guided squat, press, hinge, and pull shortlist
- Best Suspension Exercises — strap presses, rows, squats, and core shortlist
- Best Sled Exercises — sled-machine presses/hacks and power-sled pushes/drags
- Best Medicine Ball Exercises — slams, wall balls, throws, and core work
- Best Stability Ball Exercises
- Best Weighted Exercises — presses, rollouts, curls, and core accessories
- Best Assisted Exercises — partner stretches, hanging knee raises, sit-ups, and light assistance
- How to Read Exercise Instructions — demo media, step-by-step cues, and related exercises
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