Why this 1RM calculator exists
Many lifters want a useful training reference without testing a true maximum every week. 1RM Calculator keeps that task short: choose an exercise, enter a completed set, select pounds or kilograms, and review an estimated one-rep max with common training percentages.
The page is designed as a tool first. The explanation, formula comparison, result, limits, and FAQ sit around a working calculator instead of sending visitors through a sign-up flow or a long article before they can enter their numbers.
What the homepage does
The current homepage uses the Epley formula for its primary estimate and can show Brzycki as a comparison. It accepts a positive weight and a whole number from 1 to 10 reps, then updates the result and percentage table in the browser. The exercise selector covers Bench Press, Squat, Deadlift, Overhead Press, and Other.
The exercise label provides context but does not change the equation. This makes the tool easy to understand while reminding users that a formula cannot see their technique, fatigue, range of motion, equipment, or readiness.
A practical privacy boundary
The ordinary calculation is local to the current browser session. The page does not need your name, an account, a training log, or a server request to calculate the displayed estimate, and it does not intentionally place your numbers in the URL.
Local calculation does not make a result a guarantee. Your device and browser still matter, and you remain responsible for the files, data, and training decisions you bring to the page. Read the Privacy Policy for information about technical data, cookies, Google products, advertising, and support messages.
Who can use it
The tool is useful for beginners learning how rep-max estimates work, experienced lifters planning submaximal work, coaches checking a quick reference, and anyone comparing a recent set across pounds or kilograms. It can also help you turn a set such as 100 kg for 5 reps into a consistent starting point for a percentage table.
It is not a replacement for coaching, a medical professional, a formal strength test, or your own judgment. If pain, injury, illness, or an unfamiliar heavy lift is involved, seek appropriate qualified guidance.
What we care about
- A working 1RM calculator near the top of the homepage.
- Clear equations and a visible difference between estimated and tested strength.
- Usable input validation, unit conversion, keyboard access, and mobile-friendly controls.
- Training percentages that are practical reference points rather than rigid prescriptions.
- Plain explanations of accuracy limits, privacy boundaries, and responsible use.
A focused first release
The first release is intentionally an English homepage. Additional language versions, dedicated bench press or squat pages, training-plan features, RPE adjustments, and history views can be added later when each one provides a complete user task rather than a thin duplicate of the homepage.
Questions, corrections, and suggestions can be sent to support@1rmcalculator.wiki. A helpful report includes the browser, the exercise, the input range, and the result you expected.