Live 1RM estimate from a submax set, then a %1RM intensity ladder for working loads - so a prediction never pretends to be a tested gym max.
Educational strength sketch. Submax ≠ 1RM. Not medical advice, coaching clearance, or a substitute for spotters.
By Ahmet C. Toplutaş·Site owner & editor · Health tools
Last updated May 21, 2026 · Reviewed May 21, 2026 · Planning estimates only - not tax, medical, or investment advice
01
A successful set of 100 kg for five clean reps is a fact. A one-rep max of “about 117 kg” from that set is a formula projection - useful for programming, not identical to a spotter-backed single you grind under the bar today.
This page’s framing is Submax ≠ 1RM. The panel still prints a clear estimated max, then refuses to treat it as a tested gym ceiling. When Epley and Brzycki disagree by a few kilos, that delta is formula noise - not a second personal record.
Most strength programs prescribe loads as percentages of 1RM because relative intensity scales across lifters. Estimating from a hard-but-safe submax set is usually wiser than weekly all-out singles - especially for beginners, return-from-injury lifters, and anyone without reliable spotting.
That is a different job from the calories burned calculator, which sketches session energy cost, or from body-composition tools that ask about fat versus lean mass. Here the question is load selection for strength work.
Decision framing: “What working weight matches this % of my estimate?” - not “What is my official lifetime max?”
02
Percentage-based programming lets a coach write one template that still fits different absolute strengths. Eighty percent of a 100 kg squat and eighty percent of a 200 kg squat are different plates - similar relative effort if the 1RM estimates are honest.
Common bands roughly map to intents: lighter percentages for technique and speed work, mid-range for volume and hypertrophy-ish sets, heavier percentages for low-rep strength and peaking. Those bands are heuristics, not physiology law - sleep, stress, and bar speed still matter more than a tidy spreadsheet.
Reassess estimates after a training block rather than chasing a new predicted max every session. Progress that shows up as cleaner reps at the same load is still progress - Submax ≠ 1RM includes the humility to wait.
03
Epley is a common default: weight × (1 + reps/30). Brzycki uses weight × 36/(37 − reps) and can diverge more as reps rise. Lombardi applies a power curve (weight × reps^0.10). O'Conner is a linear sketch (weight × (1 + 0.025 × reps)).
All of them assume a reasonably hard set with solid form. They degrade when reps climb into the teens, when the last reps are grinders with broken technique, or when the lift is an isolation movement with a very different fatigue curve than a squat or bench.
The panel shows Epley and Brzycki side by side plus their absolute delta so formula disagreement stays visible. That compact delta is secondary - the unique affordance is the intensity ladder, not an IBW-style formula chorus band.
Prefer inputs in roughly the 2–10 rep range. The high-rep caution preset exists to show how noisy predictions become.
04
After the estimate, the panel builds working loads at 50, 60, 70, 75, 80, 85, 90, and 95% of that 1RM. Tap a rung to focus the working-load callout and to include that percentage in Share links.
That intensity ladder is intentionally different from recent renewals: not a rent-vs-buy horizon crossover strip, not a fasting 24h day clock, not an investment fee-drag bridge, and not an ideal-weight formula chorus. One interaction for Submax ≠ 1RM - percentages of an estimate, ready for a training log.
Rep-capacity targets invert a simple Epley-style relationship to sketch loads for 2, 3, 5, 8, and 10 reps from the estimated max. Use them as planning anchors when a program asks for a 5RM or an 8RM without a fresh max test.
Round to the nearest available plate in your gym. A 0.1 kg display precision is honesty about the math - not a claim that your plates match the spreadsheet.
05
Strength training carries injury risk. Warm up, learn technique before load, and use spotters or safety pins for heavy bar work. Pain that feels like injury - not normal effort - is a stop signal, not a PR opportunity.
Youth athletes, people returning from surgery, and anyone with cardiovascular or orthopedic conditions need qualified coaching and medical clearance. A calculator does not replace that.
True 1RM tests belong in rare peaking contexts with preparation - not as a weekly ego check. Submaximal estimates exist so you can train hard without treating every Monday as a meet attempt.
Recovery nutrition and energy needs are separate questions - hand off to the protein intake calculator and calorie calculator when the question shifts from bar weight to food.
06
Example A · Bench · 5s. Preset: 100 kg × 5 with Epley. Read the estimated 1RM, then tap 80% on the ladder for a strength-work load.
Example B · Squat · triples. Preset: 140 kg × 3 with Brzycki. Compare Epley↔Brzycki delta - small disagreement is normal; large disagreement is a cue to prefer lower-rep inputs.
Example C · Deadlift · lb. Preset: 315 lb × 5. Same Submax ≠ 1RM story in pounds - switch units only when your plates match.
Example D · High-rep caution. Preset: 60 kg × 12. Watch the warning callout - the ladder still prints, but the estimate is the least trustworthy of the presets.
After presets, enter your own successful set. Share only when weight, reps, units, formula, and focused percentage match what you intend to send a training partner.
If two apps disagree, check which formula they hid and whether they used a 12-rep grind as input. Visible Epley/Brzycki delta exists so that disagreement is not brand-loyal.
07
Most 1RM harm is ego-testing and percentage overconfidence - not arithmetic typos.
08
Share links snapshot weight, reps, units, formula, and focused intensity percentage. Live typing never rewrites the address bar.
09
Stop here for Submax ≠ 1RM literacy: an estimated max, an intensity ladder, and formula noise made visible. Hand off when the question is energy, protein, or composition.
10
A submaximal set (for example 100 kg × 5) is what you actually lifted. A one-rep max (1RM) estimate is a formula projection of what you might lift for a single clean rep. This page’s framing is Submax ≠ 1RM so a prediction is not mistaken for a tested gym max.
It takes your estimated 1RM and prints working loads at common percentages (about 50–95% of 1RM) used in programming. That intensity ladder is the unique affordance - different from rent-vs-buy horizon strips, fasting day clocks, investment fee-drag bridges, or ideal-weight formula choruses.
Epley is a common default. Brzycki is also widely used and can diverge more as reps rise. Lombardi and O'Conner are alternate sketches. Prefer sets in roughly the 2–10 rep range; very high-rep sets make all formulas less trustworthy.
They invert a simple Epley-style relationship to estimate loads for 2, 3, 5, 8, and 10 reps from your estimated 1RM - useful for planning, not a promise of exact performance.
Usually no. True maxes need warm-ups, spotters, and recovery. Many programs prefer periodic submax estimates or rare peaking tests. Stop if form breaks or pain appears.
No. Educational only. Injury history, youth athletes, and clinical conditions need qualified coaching and medical clearance. Calculators do not replace spotters.
No. Values hydrate from the URL on load; the address bar updates only when you use Share or Copy.
LIVE 1RM · SUBMAX ≠ 1RM
Submax ≠ 1RM ↓Scenario presets
Formula
Epley estimated 1RM
116.7 kg
From 100 kg × 5 · Submax ≠ 1RM
%1RM INTENSITY LADDER · SUBMAX ≠ 1RM
Tap a rung for the working load. This ladder is the unique affordance - programming % of an estimate, not a tested gym max.
Working load @ 80% · Strength work
93.3 kg
Programming percentages are plans, not promises. Warm up, keep form, and leave a margin for fatigue.
Epley 1RM
116.7 kg
Brzycki 1RM
112.5 kg
Epley↔Brzycki Δ
4.2 kg
REP-CAPACITY TARGETS · FROM ESTIMATED 1RM
2RM
109
3RM
106
5RM
100
8RM
92
10RM
88
Inverted Epley sketch for planning sets - not a guarantee you will hit those loads today.
Copy the link to save or share your results.