Athletes and lifters track two very different numbers: how much they can lift, and how high they can jump. The one rep max calculator estimates maximal strength from a completed set using predictive formulas. The vertical jump calculator measures jump height directly by subtracting your standing reach from your jump reach. One is a calculation from a submaximal effort; the other is a straightforward measurement protocol.
What each calculator does
The one rep max calculator takes the weight you lifted and the number of repetitions you completed — from 1 to 20 — and reports three estimates: Epley as the primary result, plus Brzycki and Lombardi. Epley adds a fixed 3.33 percent per repetition, Brzycki uses a fraction that rises toward its upper rep limit, and Lombardi applies a power curve. All three keep your selected unit and round to two decimals. The page treats the result as a planning estimate for training percentages, not a required test and not a guarantee that you can lift that load today.
The vertical jump calculator takes a standing reach and three jump-reach trials. Each trial height is jump reach minus standing reach, the highest trial is displayed with the observed range across trials. The page is deliberately narrow: it explicitly states that this reach subtraction provides no power, performance-level, readiness, training, safety, or injury conclusion. If you want power, this page will not invent it for you.
Side-by-side
| One Rep Max calculator | Vertical Jump calculator | |
|---|---|---|
| What it produces | Estimated one-repetition maximum from a completed set | Measured jump height from reach subtraction |
| Inputs | Lifted weight, repetitions (1–20) | Standing reach, three jump-reach trials |
| Outputs | Epley (primary), Brzycki, Lombardi estimates | Per-trial jump height, best trial, observed range |
| Method | Predictive formulas from a submaximal set | Direct measurement (jump reach − standing reach) |
| Typical use | Strength training percentages, progress tracking | Jump-height testing with a documented protocol |
| Scope limits | Estimate is not a safe-to-attempt guarantee | No power, readiness, or injury conclusions |
When to use which
Use the one rep max calculator when your question is about barbell strength: selecting working weights as percentages of a max, comparing similar rep sets over time, or avoiding frequent maximal attempts. Its guidance is to feed it a clean, consistent set from the same lift — same depth, same technique — because a set stopped with reps in reserve will underestimate your max, and a leg press estimate is not a squat estimate.
Use the vertical jump calculator when you want a measured, repeatable jump-height number from the documented protocol: standing reach plus three trials, best trial reported with the observed spread. The trial spread is useful information in itself — a wide range suggests inconsistent effort or technique on the day.
The two numbers complement each other if you train both qualities: the one rep max tracks strength, the vertical jump tracks a jumping movement, and progress on either should be judged with consistent measurement. Neither tool tells you whether you are ready to train at that level. Use conservative loading, proper setup, and qualified coaching or medical guidance when appropriate.
Limitations and disclaimer
Both pages provide general educational fitness information only and are not medical advice, coaching supervision, or clearance to attempt maximal lifting. Stop if you have pain, use appropriate equipment, and seek qualified professional guidance if you are new to heavy resistance training, returning from injury, or managing a health condition.