One Rep Max (1RM) Strength Calculator
Estimate your one-rep max from weight lifted and reps—with Epley, Brzycki, and Lombardi formula comparison, training percentage table, and strength standards.
Enter your details — results appear below after you calculate.
Lift details
Strength standards (optional)
Enter body weight and gender to classify your lift as Beginner, Novice, Intermediate, Advanced, or Elite.
How this One Rep Max Calculator works
Select an exercise—Bench Press, Squat, Deadlift, Overhead Press, or Custom—and enter the weight lifted (kg) and reps completed (1–12). We estimate your one-rep max (1RM) using the Epley formula (Weight × (1 + Reps ÷ 30)) as the primary result, with Brzycki (Weight × 36 ÷ (37 − Reps)) and Lombardi (Weight × Reps^0.10) shown for side-by-side comparison. When reps = 1, all three formulas return the lifted weight directly.
Your report includes a training percentage table at 50%, 60%, 70%, 75%, 80%, 85%, 90%, and 95% of estimated 1RM—with notes on typical use (warm-up, hypertrophy, strength, peaking). Use 50–60% for technique and recovery, 70–75% for volume blocks, 80–85% for strength development, and 90–95% sparingly for near-max singles. Optionally enter body weight and gender to see a strength standard classification from Beginner through Elite based on relative strength (1RM ÷ body weight) for your chosen lift.
Results include formula comparison, strength level badge, interpretation, rep-range insights, personalized recommendations, health considerations, and PDF export / share. For best accuracy, use a weight you can lift for 3–8 reps with 1–2 reps left in reserve and strict form—avoid failed reps or sets above 10 reps.
For recovery and conditioning, try our Protein Target, Body Fat Percentage, and Heart Rate Zone calculators.
One Rep Max (1RM) Strength Calculator – Bench, Squat, Deadlift & Training Percentages
Every day, thousands search "one rep max calculator", "1RM calculator", "bench press max calculator", "squat max calculator", or "deadlift 1RM calculator"—looking for a fast way to estimate maximal strength without the risk of a true max-out attempt. Whether you are programming your next squat cycle, setting bench press working weights, or tracking deadlift progress over months, knowing your estimated one-rep max (1RM) helps you pick the right training loads, periodize effectively, and measure strength gains beyond mirror or scale changes. Our free One Rep Max Strength Calculator estimates 1RM from weight lifted and reps (1–12); compares Epley, Brzycki, and Lombardi formulas; shows a percentage table at 50–95%; classifies strength as Beginner through Elite; and exports a PDF report.
Pair results with our Protein Target Calculator, Body Fat Percentage Calculator, and Heart Rate Zone Calculator for a complete strength and conditioning toolkit.
What Is a One-Rep Max (1RM)?
A one-rep max (1RM) is the heaviest weight you can lift for exactly one repetition with proper form on a given exercise. It is the most direct measure of absolute strength for that movement. Coaches and lifters use 1RM to set training percentages, track progress, and compare strength across training cycles.
True 1RM testing is demanding and carries injury risk—especially for beginners or without spotters. That is why submaximal estimation is standard practice: lift a heavy but manageable weight for 3–8 reps, then apply a validated formula to predict your max.
Absolute strength (total kg lifted) and relative strength (1RM ÷ body weight) tell different stories. A heavier lifter may bench more in absolute terms while a lighter lifter shows higher relative strength. Our optional body weight field classifies relative strength so you can benchmark progress fairly across weight classes.
1What You Enter
Exercise
- Bench Press
- Squat
- Deadlift
- Overhead Press
- Custom (any lift you name)
Lift data
- Weight lifted in kilograms (kg)
- Reps completed — 1 to 12 (best accuracy at 3–8 reps)
Optional — strength standards
- Body weight (kg)
- Gender (male / female)
Example
Bench press: 100 kg × 5 reps → estimated 1RM ≈ 116.7 kg (Epley).
2Formulas & Logic
Epley formula (default)
1RM = Weight × (1 + Reps ÷ 30)
Example: 100 kg × 5 reps → 100 × (1 + 5/30) = 116.7 kg. Widely used in strength coaching since 1985.
Brzycki formula
1RM = Weight × (36 ÷ (37 − Reps))
Example: 100 kg × 5 reps → 100 × (36/32) = 112.5 kg. Popular in powerlifting and collegiate strength programs.
Lombardi formula
1RM = Weight × Reps^0.10
Example: 100 kg × 5 reps → 100 × 5^0.10 = 117.5 kg. Sometimes preferred for slightly higher rep ranges.
Training percentages
Training load = Estimated 1RM × (Percentage ÷ 100). We show 50%, 60%, 70%, 75%, 80%, 85%, 90%, and 95%—the most common prescription bands in strength and powerlifting programs.
Strength standards
When body weight is entered, we compute relative strength (1RM ÷ body weight) and classify against exercise-specific benchmarks for Beginner, Novice, Intermediate, Advanced, and Elite tiers.
3What You Get in Results
- Estimated 1RM in kg (Epley default)
- Formula comparison — Epley, Brzycki, Lombardi side by side
- Percentage table at 50%, 60%, 70%, 75%, 80%, 85%, 90%, 95% with training use notes
- Strength standard classification (when body weight provided)
- Interpretation, insights, recommendations, and health considerations
- PDF export and share for coaches or training logs
4How We Calculate Your Results
- Validate weight lifted (> 0 kg) and reps (1–12)
- Apply Epley, Brzycki, and Lombardi formulas to the submaximal set
- Round results to one decimal place; use Epley as the primary 1RM
- Build percentage table at 50–95% of estimated 1RM
- If body weight is provided, compute relative strength and classify against exercise/gender benchmarks
- Generate interpretation, insights, recommendations, and safety notes
1RM Formulas Compared – When to Trust Each
| Formula | Best for | Rep range | Notes |
|---|---|---|---|
| Epley | General strength training | 1–10 reps | Default in this calculator; simple and reliable |
| Brzycki | Powerlifting, lower reps | 1–10 reps | Slightly conservative at higher reps |
| Lombardi | Higher-rep estimates | 1–10 reps | Can read higher than Brzycki at 6–10 reps |
| True 1RM test | Competition, peaking | 1 rep only | Most accurate but highest fatigue/injury risk |
Training Percentage Chart – What Each % Means
Based on a 100 kg estimated 1RM, here is how common training percentages translate to bar weight and typical programming use. Your calculator results use your actual estimated 1RM.
| % of 1RM | Weight (100 kg 1RM) | Typical reps | Training goal |
|---|---|---|---|
| 50% | 50 kg | 10–15 | Warm-up, technique, recovery |
| 60% | 60 kg | 8–12 | Hypertrophy volume, motor learning |
| 70% | 70 kg | 5–8 | Hypertrophy, base strength |
| 75% | 75 kg | 4–6 | Strength–size bridge |
| 80% | 80 kg | 3–5 | Strength development |
| 85% | 85 kg | 2–4 | Heavy strength, peaking prep |
| 90% | 90 kg | 1–3 | Near-max singles, neural drive |
| 95% | 95 kg | 1–2 | Max effort attempts, testing |
Strength Standards by Exercise (Male, Bodyweight Ratio)
Relative strength = estimated 1RM ÷ body weight. These approximate benchmarks classify recreational and trained lifters. Female standards use proportionally lower ratios in the calculator.
| Level | Bench | Squat | Deadlift | OHP |
|---|---|---|---|---|
| Beginner | 0.50× | 0.75× | 1.00× | 0.35× |
| Novice | 0.75× | 1.00× | 1.25× | 0.50× |
| Intermediate | 1.00× | 1.25× | 1.50× | 0.65× |
| Advanced | 1.25× | 1.50× | 1.75× | 0.80× |
| Elite | 1.50× | 1.75× | 2.00× | 0.95× |
1RM Estimation Chart by Reps (100 kg baseline, Epley)
Same weight, different reps—higher reps produce higher estimated 1RM. This table shows how rep count affects the Epley estimate for a 100 kg lift. Accuracy is best between 3–8 reps.
| Reps | Epley 1RM | Brzycki | Lombardi | 80% training wt |
|---|---|---|---|---|
| 1 | 100.0 kg | 100.0 kg | 100.0 kg | 80.0 kg |
| 3 | 110.0 kg | 109.1 kg | 112.0 kg | 88.0 kg |
| 5 | 116.7 kg | 112.5 kg | 117.5 kg | 93.3 kg |
| 6 | 120.0 kg | 115.4 kg | 119.1 kg | 96.0 kg |
| 8 | 126.7 kg | 120.0 kg | 122.6 kg | 101.3 kg |
| 10 | 133.3 kg | 125.0 kg | 125.9 kg | 106.7 kg |
| 12 | 140.0 kg | 130.4 kg | 128.9 kg | 112.0 kg |
Sample 1RM Calculations
Example A – Bench press, 80 kg × 6 reps
Epley: 80 × (1 + 6/30) = 96.0 kg estimated 1RM. Brzycki: 92.3 kg. At 75 kg body weight → 1.28× relative strength (Advanced bench). Training at 80%: 76.8 kg for 3–5 reps.
Example B – Squat, 120 kg × 5 reps
Epley: 120 × (1 + 5/30) = 140.0 kg estimated 1RM. At 85 kg body weight → 1.65× (Advanced squat). Volume day at 70%: 98 kg for 5×5. Heavy day at 85%: 119 kg for doubles.
Example C – Deadlift, 150 kg × 3 reps
Epley: 150 × (1 + 3/30) = 165.0 kg estimated 1RM. Low-rep set = high formula accuracy. 90% for near-max singles: 148.5 kg. Warm-up top set at 60%: 99 kg.
Example D – Overhead press, 50 kg × 8 reps
Epley: 50 × (1 + 8/30) = 63.3 kg estimated 1RM. Higher reps = wider formula spread. At 70 kg body weight → 0.90× (Intermediate OHP). Use 3–6 rep sets for more reliable OHP estimates next time.
Exercise-Specific 1RM Guides
Bench press
- Always use a spotter or safety arms for heavy sets and max attempts
- Pause bench and touch-and-go bench produce different 1RM values—track one style
- Best rep range for estimation: 3–6 reps with controlled descent
- Typical ratio: bench ≈ 65–75% of squat 1RM in trained lifters
- Retest every 6–8 weeks during a strength block
Squat
- High-bar, low-bar, and front squat differ—do not mix estimates
- Belted vs beltless changes bracing capacity; note which you used
- Depth standards (parallel vs below parallel) affect load—be consistent
- Best rep range: 3–5 reps; walk-out and bracing must be solid
- Warm up hips and ankles before heavy squat sessions
Deadlift
- Conventional vs sumo deadlift are separate lifts with different 1RMs
- Straps vs no straps, mixed grip vs double overhand—log your setup
- Deadlift fatigues the CNS quickly—limit heavy deadlift days to 1×/week
- Best rep range: 1–5 reps; avoid grinding reps with rounded back
- Often the highest absolute 1RM of the three powerlifts
Overhead press (OHP)
- Strict press only—no leg drive (that is push press, a different lift)
- Standing vs seated changes load; standing is standard for 1RM
- Smallest absolute loads of the main barbell lifts—small jumps matter
- Best rep range: 3–6 reps; lockout and bar path over forehead
- Shoulder mobility limits many lifters—warm up rotator cuff thoroughly
Rep Ranges & Training Goals
| Rep range | % of 1RM | Primary goal | Notes |
|---|---|---|---|
| 1–3 reps | 85–100% | Maximal strength, neural drive | High fatigue; use sparingly in training |
| 4–6 reps | 75–85% | Strength + some hypertrophy | Sweet spot for most strength programs |
| 6–10 reps | 65–75% | Hypertrophy (muscle size) | Good for accessory and volume work |
| 10–15 reps | 55–65% | Muscular endurance, pump work | Poor 1RM estimate source—avoid for max prediction |
| 15+ reps | <55% | Endurance, conditioning | Not suitable for 1RM formulas |
Understanding Strength Levels
Beginner
New to barbell training or returning after a long break. Focus on learning movement patterns at 50–70% of estimated max. Linear progression (add 2.5–5 kg weekly) works well for 3–6 months.
Novice
3–12 months of consistent training. Still gaining strength quickly on basic programs. Most work at 65–80% of 1RM. Retest estimates every 4–6 weeks as numbers climb.
Intermediate
1–3+ years of structured lifting. Progress slows—periodization required. Wave loading between 70–90%. Monthly or block-based 1RM retests.
Advanced
Years of dedicated training. Gains are hard-won. Peaking blocks, deloads, and autoregulation (RPE/RIR) become essential. True 1RM tests 2–4×/year.
Elite
Top-tier relative strength for your body weight. Competitive powerlifters, weightlifters, or genetic outliers. Programming is highly individualized with coach oversight.
Female Strength Standards (Bodyweight Ratio)
Female lifters typically reach the same classification tiers at lower bodyweight ratios than males due to differences in muscle mass distribution and hormonal profile. Our calculator applies these adjusted benchmarks automatically when female is selected.
| Level | Bench | Squat | Deadlift | OHP |
|---|---|---|---|---|
| Beginner | 0.38× | 0.56× | 0.75× | 0.26× |
| Novice | 0.56× | 0.75× | 0.94× | 0.38× |
| Intermediate | 0.75× | 0.94× | 1.13× | 0.49× |
| Advanced | 0.94× | 1.13× | 1.31× | 0.60× |
| Elite | 1.13× | 1.31× | 1.50× | 0.71× |
Periodization Using Your 1RM
Accumulation (4–6 weeks)
Higher volume at 65–75% of 1RM. 3–4 sets of 6–10 reps. Build work capacity and muscle mass. Example: 70% for 4×8 on main lifts.
Intensification (3–4 weeks)
Lower reps, higher intensity at 75–85%. 4–5 sets of 3–5 reps. Strength focus. Example: 80% for 5×3, adding 2.5 kg weekly if all sets complete.
Realization / Peaking (1–2 weeks)
Heavy singles and doubles at 85–95%. Low volume, high neural demand. Optional true 1RM test at end of block. Deload the week after.
Deload (1 week)
Cut volume 40–50% and intensity to 60–70% of 1RM. Recover before next accumulation phase. Prevents overtraining and joint wear.
Warm-Up Protocol Before Heavy Sets
Based on a 100 kg estimated 1RM working weight. Scale each percentage to your actual 1RM. Rest 60–90 sec between warm-up sets; 3–5 min before top working sets.
| Set | % of 1RM | Weight | Reps | Purpose |
|---|---|---|---|---|
| 1 | Empty bar | 20 kg | 10 | Groove pattern, shoulder/elbow prep |
| 2 | 40% | 40 kg | 8 | Blood flow, light tension |
| 3 | 60% | 60 kg | 5 | Progressive loading |
| 4 | 75% | 75 kg | 3 | Neural activation |
| 5 | 85% | 85 kg | 1–2 | CNS primer before work sets |
| 6+ | Working | 80–90% | 3–5 | Main training sets |
Kilograms to Pounds Conversion
This calculator uses kilograms. To convert: kg × 2.205 = lb and lb ÷ 2.205 = kg. Common gym plate conversions:
| kg | lb | Common use |
|---|---|---|
| 20 kg | 44 lb | Empty bar (standard) |
| 60 kg | 132 lb | Beginner bench working weight |
| 100 kg | 220 lb | Intermediate bench 1RM zone |
| 140 kg | 309 lb | Intermediate squat 1RM zone |
| 180 kg | 397 lb | Advanced deadlift 1RM zone |
| 225 kg | 496 lb | Classic 225 lb bench milestone |
Benefits of Tracking Your 1RM
- Objective progress — strength gains are measurable even when body weight is stable
- Smarter programming — prescribe sets at exact percentages instead of guessing
- Plateau detection — if estimated 1RM stalls for 3+ weeks, adjust volume, intensity, or recovery
- Injury risk reduction — submaximal estimation avoids frequent max-out attempts
- Goal setting — target milestones like 1× bodyweight bench or 2× bodyweight deadlift
- Coach communication — share PDF reports with trainers for program design
Who Should Use This Calculator?
Gym beginners
Estimate max safely without testing. Learn what 70% or 80% feels like before loading heavy. Pair with a coach for form checks.
Intermediate lifters
Program percentage-based cycles. Compare Epley vs Brzycki. Track relative strength as body weight changes during bulk or cut phases.
Athletes & coaches
Quick 1RM estimates from training logs. Export PDF for athlete records. Use percentage table for in-season vs off-season loading.
How to Test or Estimate Your 1RM Safely
- Warm up thoroughly — 5–10 min cardio, dynamic mobility, then progressive sets (empty bar → 50% → 70% → 85%).
- Use a submaximal set — pick a weight you can lift for 3–8 reps with 1–2 reps left in reserve (RIR). Enter it here instead of maxing out.
- True 1RM testing — only when experienced, with spotters for bench, and after a proper peaking block. Attempt singles with 3–5 min rest between tries.
- Retest periodically — every 4–12 weeks as programs advance; daily maxing causes fatigue and raises injury risk.
- Log consistently — same exercise variation (pause vs touch bench, belted vs beltless squat) for comparable trends.
Common Mistakes When Using a 1RM Calculator
- Using reps above 10—formulas lose accuracy; cap at 12 and prefer 3–8 reps.
- Grinding ugly reps—if the last rep was a failed half-rep, the estimate overstates true max.
- Mixing lift variations—sumo deadlift 1RM ≠ conventional; compare like with like.
- Maxing out every session—submaximal estimation is safer and sufficient for programming.
- Ignoring body weight—absolute load alone does not show relative strength; enter body weight for standards.
- Treating estimates as competition attempts—always use spotters and proper equipment for true max tests.
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