Strength Percentages Calculator

The calculator converts your one-rep max into training loads using: Load = 1RM × (Percent ÷ 100). If rounding is enabled, the load is adjusted to your selected increment.

When estimating 1RM from a submax set, the chosen rep formula converts lifted weight (W) and reps (R) into an estimated max. Lower rep ranges usually estimate better.

1. Pick Unit (kg or lb) and keep it consistent.
2. Choose Direct 1RM if you know your tested max.
3. Or pick Estimate 1RM, then enter weight, reps, and a formula.
4. Select Rounding to match plates and bar loading realities.
5. Optionally set a custom Percent list for your program.
6. Press Calculate to view the table above the form, then export CSV or PDF.

Example below uses a 1RM = 100 kg with no rounding.

How percentage loading supports consistency

Percentage loading converts your max into repeatable targets, keeping effort comparable across weeks. For example, if your squat 1RM is 160 kg, 75% is 120 kg and 85% is 136 kg. That simple scaling helps coaches prescribe volume blocks (60–75%) and intensity blocks (80–90%) without guessing. It also reduces day-to-day noise: even if you feel flat, you can round down slightly and still stay within the intended training zone.

Estimating a max when testing is not ideal

Many athletes avoid frequent true-max testing to limit fatigue and risk. A hard set of 3–8 reps can produce an estimate. This calculator offers multiple rep formulas because different lifters and rep ranges behave differently. If you complete 100 kg for 5 reps, most formulas place your estimated 1RM near 112–117 kg. Treat the estimate as a starting point, then update it after a few sessions using real performance.

Rounding loads to match equipment

Gyms rarely allow perfect numbers, so rounding matters. Rounding to 2.5 kg or 5 lb mirrors common plate jumps and keeps session setup fast. For volume work, rounding down preserves bar speed and technique. For top singles, rounding up can be appropriate when you are fresh and recovered. The calculator lets you choose direction and decimals, so the table matches your plates, collars, and bar system.

Using zones to select reps and rest

Strength is not only about heavier weights; it is also about appropriate dose. At 60–70%, many lifters tolerate 4–6 sets of 6–10 reps with shorter rests. At 80–90%, 3–6 sets of 2–5 reps with longer rests often improves force production and technical quality. Above 90%, use singles or doubles, full recovery, and form. Pair the table with your program’s weekly volume targets to manage fatigue.

Tracking progress with exports and reviews

Consistent logging turns percentages into feedback. Export the table, note the bar speed and perceived effort, and compare outcomes across weeks. If 85% moves faster than last month, your estimated 1RM may be low. If 75% feels like a grind, reduce volume or recalculate using a recent set. Small adjustments, made from numbers, help you progress without constant max attempts.

1) Which estimate formula should I choose?

Start with Epley or Brzycki for 1–10 reps. If your estimates feel consistently high or low, switch formulas and compare against a recent single. Use the one that best matches your real performance over time.

2) Should I round loads up or down?

Round down for higher-volume days to protect technique and speed. Round up for heavy singles only when you are fresh and have full rest. Consistent rounding matters more than chasing perfect numbers.

3) Why do my percentages feel harder some days?

Sleep, stress, soreness, and nutrition change readiness. If a target load feels unusually heavy, stay in the same percentage zone but reduce the weight slightly or cut one set. Keep the intent, manage fatigue.

4) Can I use custom percent lists?

Yes. Enter your program’s exact percentages, separated by commas or spaces. This is useful for peaking plans (for example, 82.5–97.5%) or for technique blocks that focus on 60–72%.

5) Does switching between kg and lb change results?

The math is identical, but rounding depends on your plates. Choose the unit you actually load in the gym, then select an increment that matches your smallest practical jump.

6) Is it safe to train at 95–100% regularly?

Not for most lifters. Reserve 95%+ for testing or short peaking phases, and prioritize recovery, spotters, and flawless technique. Most strength gains come from consistent work in the 70–90% range.