# 1RM Calculator - One Rep Max

> Util for estimating max lifts

Canonical page: [https://chrome-stats.com/d/id681279192](https://chrome-stats.com/d/id681279192)

## Overview

- **ID:** `id681279192`
- **Platform:** Apple
- **Type:** Apple app
- **Status:** Available
- **Publisher:** David Bai
- **Category:** Health & Fitness
- **Rating:** 4.50 / 5 (222 ratings)
- **Version:** 4.5
- **Last updated:** 2019-05-20
- **First published:** 2013-08-10
- **Size:** 20 MB
- **Data as of:** 2026-09-20
- **Store listing:** [Apple App Store](https://apps.apple.com/us/app/1rm-calculator-one-rep-max/id681279192)
- **Privacy policy:** [http://www.davbai.com](http://www.davbai.com/)

## Description

1RM Calculator helps you determine your 1-rep max by entering the weight you lifted and the reps you performed to see an estimated max. It also lets you compare different rep schemes and track your strength progression over time.

Note: This tool provides estimates. Always warm up and use a spotter for safety. Pro Version includes ad-free usage, saved lifts and history charts, more formulas, multiple maxes (up to 10), lbs/kg switch, and a percentage view from 50% to 125% of your 1RM.

## Rankings

- #101,530 — Overall

## Review summary

Users broadly praise the app for being simple and fast to calculate 1RM and to show quick percentages, making workout planning easier. However, a large portion report paying for the Pro upgrade only to find features not unlocked or the app crashing when accessing paid features. The Pro/paywall presents reliability and usability frustrations, with several calls for ongoing support and updates. Overall, the app delivers a lightweight, straightforward 1RM calculator, but its monetization-linked bugs and stability issues significantly undermine user experience.

### Pros

- Simple, fast to use for calculating 1RM.
- Provides immediate 1RM value and percentage outputs for quick reference.
- Useful for planning workouts and tracking progress.
- Highly regarded as a solid, lightweight max-rep calculator.

### Cons

- Pro upgrade often does not unlock features after payment.
- Upgrading can cause crashes or make the app unusable when accessing paid features.
- The free version appears limited and relies on Pro for core functionality (paywall concern).
- General instability and glitchy behavior reported by users after upgrades.

## Similar extensions and apps

- [One Rep Max](https://chrome-stats.com/d/id6467693942) — 3.00 / 5
- [One Rep Max - 1RM Calculator](https://chrome-stats.com/d/id1367332610) — 5.00 / 5
- [1RM Calculator](https://chrome-stats.com/d/id1566775126) — 4.90 / 5
- [1RM - One Rep Max Calculator](https://chrome-stats.com/d/id6480014506)
- [1 Rep Max Calc](https://chrome-stats.com/d/id6449542297) — 4.50 / 5
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- [One Rep Max: 1RM Calculator](https://chrome-stats.com/d/id950621710) — 4.40 / 5
- [My 1 Rep Max](https://chrome-stats.com/d/id1317637753) — 4.40 / 5
- [MaxRep: 1RM Calculator](https://chrome-stats.com/d/id6764419279)
- [Streetlifter - Calculate 1RM](https://chrome-stats.com/d/id6747384909)
- [1-RM](https://chrome-stats.com/d/id1274191954) — 4.80 / 5
- [1RM Weight Lifting Rep Max](https://chrome-stats.com/d/id1466865497) — 2.30 / 5

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Source: [Chrome-Stats](https://chrome-stats.com/d/id681279192)