How accurate are 1RM calculators?

1RM calculators are generally accurate within 5-10% when used with rep ranges under 10. The accuracy depends on factors like training experience, muscle fiber composition, and the specific formula used. Our calculator uses 7 different formulas to give you the most comprehensive estimate.

Which 1RM formula is most accurate?

The Epley formula is most widely used and accurate for most people, especially with rep ranges of 2-10. However, different formulas work better for different individuals. Brzycki tends to be conservative, while Lombardi works well for powerlifters. Our calculator shows all 7 formulas so you can compare.

Can I use this for any exercise?

Yes, you can use 1RM calculators for any compound exercise like bench press, squat, deadlift, overhead press, and rows. The formulas are based on general strength principles that apply across exercises, though they're most accurate for compound movements.

What rep range should I use for the most accurate calculation?

For best accuracy, use rep ranges between 2-10 reps. The sweet spot is 3-8 reps where most formulas perform optimally. Avoid using very high rep ranges (15+) as the formulas become less reliable due to muscular endurance factors.

How often should I recalculate my 1RM?

Recalculate your 1RM every 4-6 weeks or whenever you notice significant strength gains. For beginners, monthly calculations work well. Advanced lifters might recalculate every 6-8 weeks. Always use recent max effort sets for the most accurate results.

1RM Calculator - Calculate Your One Rep Max

1RM Calculator

Exercise

Weight

Reps

Enter the weight and reps from your recent heavy set to estimate your one rep max.

Real 1RM Calculator Examples - 6 Popular Lifts

See how to calculate your one rep max from common lifting scenarios with exact percentages

89% of 1RM

Bench Press

225 × 5 = 253 lbs

5 reps @ 225 lbs → 253 lbs max

If you can bench press 225 lbs for 5 reps, your estimated 1RM is 253 lbs. Use 230 lbs (90%) as your training max for programming.

94% of 1RM

Squat

315 × 3 = 334 lbs

3 reps @ 315 lbs → 334 lbs max

Squatting 315 lbs for 3 reps suggests a 334 lb 1RM. Most powerlifting programs would use 300 lbs (90%) for working sets.

97% of 1RM

Deadlift

405 × 2 = 416 lbs

2 reps @ 405 lbs → 416 lbs max

A 405 lb double on deadlift calculates to a 416 lb max. For 5/3/1 programming, you'd base percentages off 375 lbs.

80% of 1RM

Overhead Press

135 × 8 = 168 lbs

8 reps @ 135 lbs → 168 lbs max

Pressing 135 lbs for 8 reps indicates a 168 lb 1RM. Military personnel often use 150 lbs (90%) for strength standards.

86% of 1RM

Barbell Row

185 × 6 = 215 lbs

6 reps @ 185 lbs → 215 lbs max

Rowing 185 lbs for 6 reps gives you a 215 lb 1RM. Use this to balance your pressing strength - aim for 75% of bench press 1RM.

91% of 1RM

Front Squat

225 × 4 = 247 lbs

4 reps @ 225 lbs → 247 lbs max

Front squatting 225 for 4 reps equals 247 lb max. Front squat 1RM should be 80-85% of back squat for balanced leg development.

1RM Percentage Chart by Rep Range

Visual guide showing the relationship between reps and percentage of your one rep max

1 rep

100%

Max Strength

2 reps

97%

Max Strength

3 reps

94%

Max Strength

4 reps

91%

Strength

5 reps

89%

Strength

6 reps

86%

Strength

8 reps

80%

Hypertrophy

10 reps

75%

Hypertrophy

12 reps

70%

Hypertrophy

15 reps

65%

Endurance

20 reps

60%

Endurance

Max Strength (90-100%)

Strength (80-89%)

Hypertrophy (70-79%)

Endurance (60-69%)

Quick 1RM Reference Chart - Common Weights

Instant 1RM estimates for standard barbell weights and rep ranges

Weight	2 reps	3 reps	5 reps	8 reps	10 reps	12 reps
135 lbs	139 lbs	143 lbs	152 lbs	169 lbs	180 lbs	193 lbs
185 lbs	190 lbs	196 lbs	208 lbs	231 lbs	247 lbs	264 lbs
225 lbs	232 lbs	239 lbs	253 lbs	281 lbs	300 lbs	321 lbs
315 lbs	324 lbs	334 lbs	354 lbs	394 lbs	420 lbs	450 lbs
405 lbs	417 lbs	430 lbs	455 lbs	506 lbs	540 lbs	579 lbs
495 lbs	510 lbs	525 lbs	556 lbs	619 lbs	660 lbs	707 lbs

* Values calculated using the average of all 7 formulas. Individual results may vary by ±5%

1RM Strength Standards by Experience Level

Compare your calculated 1RM to strength standards for bench press, squat, and deadlift

Level	Bench Press	Squat	Deadlift
Beginner	Bodyweight × 0.75	Bodyweight × 1.25	Bodyweight × 1.5
Intermediate	Bodyweight × 1.25	Bodyweight × 1.75	Bodyweight × 2.25
Advanced	Bodyweight × 1.75	Bodyweight × 2.25	Bodyweight × 2.75

* Standards shown as multipliers of bodyweight. Calculate your 1RM and divide by bodyweight to compare.

Ideal Lift Ratios for Balanced Strength

Use your 1RM to check if your strength is balanced across major lifts

Upper/Lower Balance

Bench Press100% (baseline)

Squat130-140%

Deadlift150-160%

* If your bench is 225 lbs, aim for 315 lbs squat and 360 lbs deadlift

Push/Pull Balance

Bench Press100% (baseline)

Barbell Row75-85%

Overhead Press60-67%

* Balanced push/pull ratios help prevent shoulder injuries

Bodyweight Milestones

Bench Press:1.5x bodyweight = Advanced

Squat:2x bodyweight = Advanced

Deadlift:2.5x bodyweight = Advanced

OHP:1x bodyweight = Advanced

Competition Standards

Powerlifting Total:7x bodyweight = Elite

Wilks Score:400+ = National level

DOTS Score:450+ = Elite

IPF Points:500+ = World class

How the 1RM Calculator Works

What is 1RM?

Your one rep max (1RM) is the maximum weight you can lift for a single repetition with proper form. Our calculator estimates it safely using multiple reps.

7 Scientific Formulas

Epley, Brzycki, Lombardi, O'Conner, Mayhew, Wathan, and Lander formulas - averaged together for the most accurate 1RM calculation.

Training Percentages

Get personalized percentages for max strength (90-100%), hypertrophy (70-79%), and muscular endurance (60-69%) training.

Using Your 1RM for Popular Programs

How to apply your calculated one rep max to popular strength training programs

5/3/1 (Wendler)

Use 90% of your 1RM as training max

• Week 1: 65%, 75%, 85%
• Week 2: 70%, 80%, 90%
• Week 3: 75%, 85%, 95%
• Week 4: Deload 40-60%

Starting Strength

Begin at 60% of 1RM for work sets

• 3x5 linear progression
• Add 5-10 lbs per session
• Reset at 90% when stalled
• Calculate new 1RM monthly

StrongLifts 5x5

Start at 50% of calculated 1RM

• 5x5 on main lifts
• Progress: 5 lbs per workout
• Deload to 90% after 3 fails
• Test new 1RM every 12 weeks

Texas Method

Volume day at 90% of 5RM (80% 1RM)

• Monday: 5x5 @ 90% of 5RM
• Wednesday: 2x5 @ 80% of Monday
• Friday: 1x5 PR attempt
• Recalculate 1RM weekly from Friday

Complete Guide to 1RM Testing and Calculation

When to Calculate vs Test Your 1RM

Calculate Your 1RM When:

• You're a beginner or intermediate lifter
• Training alone without spotters
• Programming requires percentages
• Tracking progress over time
• Injured or returning from layoff

Test Your 1RM When:

• Competing in powerlifting
• Experienced with heavy singles
• Have qualified spotters
• Peaking for competition
• After 12-16 week training cycle

Best Rep Ranges for Accurate 1RM Calculation

1-3 reps:Most accurate (±2-3%)

4-6 reps:Very accurate (±3-5%)

7-10 reps:Good accuracy (±5-8%)

11-15 reps:Less reliable (±8-12%)

Common 1RM Calculator Mistakes to Avoid

❌ Using high reps (15+): Accuracy drops significantly above 10 reps
❌ Not using true max effort: Your set must be close to failure for accuracy
❌ Ignoring form breakdown: Only count reps with proper technique
❌ Testing too frequently: Recalculate every 4-6 weeks maximum
❌ Using 100% of calculated max: Always use 90% for programming safety

One Rep Max Calculator Tool

1RM Calculator

Real 1RM Calculator Examples - 6 Popular Lifts

Bench Press

Squat

Deadlift

Overhead Press

Barbell Row

Front Squat

1RM Percentage Chart by Rep Range

Quick 1RM Reference Chart - Common Weights

1RM Strength Standards by Experience Level

Ideal Lift Ratios for Balanced Strength

Upper/Lower Balance

Push/Pull Balance

Bodyweight Milestones

Competition Standards

How the 1RM Calculator Works

What is 1RM?

7 Scientific Formulas

Training Percentages

Using Your 1RM for Popular Programs

5/3/1 (Wendler)

Starting Strength

StrongLifts 5x5

Texas Method

Complete Guide to 1RM Testing and Calculation

When to Calculate vs Test Your 1RM

Calculate Your 1RM When:

Test Your 1RM When:

Best Rep Ranges for Accurate 1RM Calculation

Common 1RM Calculator Mistakes to Avoid

Frequently Asked Questions About 1RM Calculators

How accurate are 1RM calculators?

Should I test my actual 1RM?

What is a Training Max?

Which formula is the most accurate?

Can I use this for any exercise?

How often should I recalculate my 1RM?

What rep range gives the most accurate results?

Why do different calculators give different results?

How do I know if my calculation is realistic?

Can beginners use 1RM calculators?

What if I miss reps during my test?

Should men and women use different formulas?

How does age affect 1RM calculations?

What's the difference between predicted and actual 1RM?

Can I use 1RM for bodyweight exercises?