Weight, percentage, and effort
are not the same thing.
01
1RM
Your one-rep max. The most weight you can lift once with an acceptable technique for a specific exercise. It is different for your squat, deadlift, snatch, etc.
02
%1RM
How heavy your prescribed load is compared with that max. If your max is 200 lb, 75% is 150 lb. It's a weight calculation, not a feeling.
03
RPE / RIR
How hard a set felt / how many good reps you had left. RPE 8 commonly means about two more reps were possible. It doesn't mean 80% of your max.
Full Sent rule: When a session prescribes specific sets, reps, percentages, or approved loading ranges, follow those instructions. These learning tools don't replace a real workout prescription.
01 / ESTIMATED MAX TOOL"I lifted this for five reps.
"I lifted this for five reps.
What might my 1RM be?"
You do not need to test a true max to get a rough starting point. Enter a weight and the number of technically sound repetitions you completed in one challenging set. We'll show two common estimates. These are predictions—not verified PRs.
THE LIFT ESTIMATOR
CHOOSE YOUR LIFTEach lift keeps its own numbers as you switch.
Numbers shown when you first select a lift are illustrative examples. Replace them with your own recorded sets.
lb
LIGHTERHEAVIER
reps
1 REP12 REPS
For a useful estimate: the set should have been reasonably close to your technical limit, with consistent range of motion. If those reps felt easy, the calculator will likely underestimate what you could lift. Sets above about 10 reps are more uncertain.
Squat estimates work best when the set was challenging and consistent in depth and technique.
SQUAT · ROUGH ESTIMATED 1RM · EPLEY
lb
225 × (1 + 5 ÷ 30) ≈ 263 lb
SECOND OPINION · BRZYCKI lb
DIFFERENCE BETWEEN FORMULAS lb
Squat numbers shown here are demonstration values until you enter your own set.
This difference is not a scientifically established confidence interval. Both formulas are rough guides. Actual strength varies by athlete, exercise, technique, and fatigue.
Squat example: 225 lb × 5 strong reps → Epley estimate ≈ 262.5 lb.
What is Epley?
A simple equation that takes the weight and repetitions you completed to estimate what one all-out rep might be: weight × (1 + reps ÷ 30). For one rep, we use the actual lifted weight. This is an estimate, not a test result.
What is Brzycki?
A second common equation: weight × 36 ÷ (37 − reps). It often gives a different result. Showing both helps athletes see that calculated maximums are not perfectly exact.
02 / PERCENTAGE PLANNERTurn your max into
50–100% · EVERY 5%
Turn your max into
training weight.
Once you know a tested max—or have a cautious estimate—the math is straightforward. Select the percentage to see the corresponding weight. The chart is a reference, not a workout plan.
lb
Only choose this when your number comes from a recorded, successful lift with a valid standard.
%
50%100%
If the workout says 75%, move the slider to 75—not to what feels like RPE 7.5.
CALCULATED WEIGHT AT 75%
lb
Based on your selected Squat: 263 lb estimated max. Rounded to nearest 2.5 lb for the display; use the approved increment and loading instructions in your session.
Your percentage-to-weight chart
The longer the bar, the heavier the calculated load. Select different percentages above to explore.
Example loads are rounded for readability, not guaranteed available plate combinations. Avoid assuming these values prescribe the number of repetitions.
03 / HOW HARD DID IT FEEL?RPE & RIR.
RPE & RIR.
Plain English.
RIR means reps in reserve: how many more quality reps you think you could have done. RPE is a matching 1–10 strength-training effort score. Use this scale for lifting sets, not as a direct replacement for endurance workout intensity.
RPE
6 · EASIER10 · MAXIMUM
≈ 2 repsLIKELY REPS LEFT
Hard, but controlledHOW TO THINK ABOUT IT
How to answer honestly
After the last rep, ask: “If I absolutely needed to, how many more could I do with the same acceptable technique?”
If the answer is two, call that about RPE 8. If you couldn't do another good rep, that's around RPE 10.
This is a skill. Beginners are often less accurate, and a squat can feel different from a press even at the same percentage.
Quick reference
RPE 64+ reps left
RPE 7~3 reps left
RPE 8~2 reps left
RPE 9~1 rep left
RPE 100 reps left
Approximate strength-set descriptions, not a universal conversion between RPE and %1RM. Half-point RPE ratings represent in-between judgments.
04 / ESTIMATED REP-LOAD CURVESee how possible weights
1–10 REPS · ESTIMATED
See how possible weights
change with more reps.
This chart uses the Epley estimate selected above to model a possible near-limit load for different rep counts. It can help you see why a weight suitable for one rep usually isn't the same weight you'd use for ten.
Illustrative maximum-rep load by repetitions
Based on the active 1RM value from your percentage planner.
Model: estimated load = 1RM ÷ (1 + reps ÷ 30), with one rep set equal to 1RM. Individual rep strength varies considerably. This is not permission to test these loads or a replacement for programmed loading.
Why estimates change
People have different strength-endurance profiles. Someone may be excellent at heavy singles, another at sets of eight. Range of motion, movement, fatigue, and how hard the original set really was all matter.
What if the graph seems wrong?
That's normal. Use actual training records, conservative judgment, and approved prescriptions to refine your understanding. A graph cannot tell whether a rep was technically sound or safe.
05 / USE IT IN TRAINHEROICRead the prescription.
Read the prescription.
Then do the work.
01
Look for sets, reps, and percentages
Illustrative: “Back squat — 4 sets of 5 reps at 75%.” That means four prescribed working sets of five at the calculated percentage. It does not mean you warm up with four sets of five.
02
Warm up separately
Warm-up sets prepare you to perform the actual work. They are not automatically part of the four working sets. The day's approved programming controls the plan.
03
Use RPE when it's requested
If a set specifies RPE, use your perception of effort as directed. When an exact percentage is prescribed, don't quietly replace it with a guessed RPE-based weight.
04
Log real numbers
Record the load you actually used, completed reps, and—if requested—RPE. An estimated 1RM is useful context, but it is not a tested one-rep PR.
When fatigue hits
Sometimes a percentage feels unexpectedly heavy. Check readiness, technique, recovery, and the prescription; consult the coach's approved adjustment rather than inventing one.
When you're new
You don't need a risky all-out 1RM test. Learn positions, use manageable loads, and build reliable training data first.
When a lift causes pain
Stop the painful activity. Seek appropriate qualified in-person guidance rather than forcing a number the calculator suggested.
The sample squat set above is purely educational, not a real full Sent Project workout. Real sessions follow the published athlete tiers, loads, and approved modifications.
06 / FAQQuestions athletes
Questions athletes
actually ask.
Is estimated 1RM the same thing as my PR?
No. Your tested PR is a successful actual lift. An e1RM is a model-derived guess based on one or more sets. Label and log these separately.
If I can lift 185 lb for 5 reps, can I definitely lift the estimate once?
No. The estimate depends on whether those five reps were near your technical limit and how you perform heavy singles. It is a guide for understanding training loads, not a guarantee or attempt recommendation.
Does RPE 8 equal 80%?
No. RPE 8 is about two additional good reps remaining. 80% is a specific fraction of a known max. A particular 80% set may feel easier or harder depending on the number of reps, exercise, and athlete.
Which one-rep-max formula should I trust?
Neither should be treated as exact. We show Epley and Brzycki because they are common and easy to explain. For many athletes, a recent high-quality set and real performance history are more informative than a single isolated equation.
Why do heavier sets sometimes feel easier than lighter sets?
Repetitions, rest, fatigue, technique, the exercise involved, and daily readiness change difficulty. A single heavy rep can feel manageable while a much lighter set of 15 can feel brutal.
How many reps are too many for estimating 1RM?
Estimates usually become less dependable at higher repetition counts. This tool allows up to 12 for teaching, but treat sets above roughly 10 reps as especially rough and avoid using them to choose risky heavy attempts.
Can I use the calculator for kettlebell work or machines?
It is designed primarily as a general barbell-style teaching tool. Movement differences, unilateral loading, machine leverage, and skill requirements can make estimates much less transferable. Don't convert between exercises as though they share a max.
If I don't have a coach with me, should I test a true max?
You do not need to. Build technique and training consistency with appropriate loads; a qualified coach can help determine whether max testing is suitable and how to do it safely.
full Sent Project / FIELD MANUAL
Know the number.
Respect the work.
Use these tools to understand the prescription—not to chase a number at the expense of technique, recovery, or intelligent training.
Further reading: Zourdos et al., strength-training RPE/RIR · Application of RIR-based RPE. Epley and Brzycki are conventional estimation equations, not official full Sent Project test standards.
Educational resource from full Sent Project, independent of and not endorsed by CrossFit, LLC. All calculators provide estimates only. Follow current session instructions and applicable movement standards.
