# 1RM Calculator - One Rep Max — Util for estimating max lifts

> Calculate estimated one-rep maximum lifts based on weight and repetitions performed. (iPhone/iPad app by David Bai.)

- Source: https://appshunter.io/ios/app/1rm-calculator-one-rep-max/id681279192 (this page in markdown: same URL + `.md`)
- Developer: [David Bai](https://appshunter.io/developer/609405595)
- Category: Health & Fitness, Sports
- Price: Free with in-app purchases
- Rating: 4.50/5 from 222 App Store ratings · 38 written reviews indexed
- Age rating: 4+
- Requires: iOS 12.1 · 20 MB
- Languages: American English
- Released: 2013-08-10
- Data updated: 2026-09-04
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/1rm-calculator-one-rep-max/id681279192/reviews.md

## What is 1RM Calculator?

1RM Calculator is a tool to help you determine your 1-rep max! Because of the nature and stress of attempting a 1-rep max, this utility allows you to enter in a weight you successfully lifted at the number of reps you performed in order to see what your estimated 1-rep max is. 

This not only helps give you an idea of the weight to attempt when actually performing a 1-rep max but also to gauge your strength and compare different rep schemes performed at different reps. If one week you were able to bench press 190 lbs at 6 reps and the next week you did 200 for 5, this app gives you a way to compare the two as best as possible (190 lbs @ 6 reps gives a 1-rep max estimate of 223 lbs vs. 200 lbs @ 5 reps gives a 1-rep max estimate of 227 lbs) 

**** PRO VERSION FEATURES ****
Upgrade to the Pro version to get all the settings and features!
- Ad free experience
- Save your lifts and track your history and progress
- Historical chart and list views, categorized by exercise
- More formulas in order to best estimate your maximums
- Multiple rep maxes (up to 10)
- Ability to switch between lbs and kgs
- Percentage view that shows anywhere from 50% to 125% of your 1-rep max

1RM Calculator is only intended to give estimates based on the data you enter. Since these are calculated values they may vary with actual measured values. Always ensure you have a spotter, and work your way up to your limit with more than adequate warmup to prevent injuries.

## Key features

- Estimate 1-rep max
- Track lift history and progress
- Historical chart and list views
- Multiple estimation formulas
- Calculate multiple rep maxes
- Switch between lbs and kgs
- View percentages of 1-rep max

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Pro Upgrade | $1.99 | one-time |


## Recent user reviews (10 of 38)

All indexed reviews: https://appshunter.io/ios/app/1rm-calculator-one-rep-max/id681279192/reviews.md

### 5/5 — Jack

*2026-07-30*

This app is so great! It has helped me figure out ratios with all my different routines. Thanks RM1.

### 2/5 — Pro glitch

*2024-07-24*

For everyone who is having issues with pro not workin, simply click restore purchase on the pro ad screen. 2 stars because this isn’t fixed

### 3/5 — Great ideas, needs some polishing.

*2023-09-29*

I love that I can actually build my own programs and set different methods to drive progression. 

Some of the ui and quality of life features could use some work

### 1/5 — Upgrade

*2022-08-31*

I paid for the upgrade but it won’t let me access those features.

### 1/5 — Didn’t switch over don’t pay

*2022-08-15*

Upgraded to pro for $2 didn’t switch from basic to pro

### 2/5 — Pro not working?

*2022-07-29*

Hello. I hope the developers read this and reach out to me. The app itself is very simple to use and has everything I was looking for. I upgraded to pro because the workout selection was very minimal, and $2 didn’t seem like a lot to me, since this was an app I was planning on using daily. However my credit card was charged and my app still says basic. I tried closing the app completely and even restarting my phone entirely. Such a bummer that this happened. Seems that by reading other reviews I wasn’t the only one this happened to. Users beware!

### 2/5 — Ok-ish

*2022-07-10, version 4.5*

UI leaves something to be desired. It is pretty simple but missing some features that I believe should be available. 

Things that should be available:

The ability to re-arrange your exercises so you can get a specific order. 

The ability to re-name exercises. 

The ability to deleted exercises.

### 5/5 — very accurate

*2022-03-08*

very accurate

### 1/5 — App doesn’t give you access to Pro

*2022-03-02*

Bought the pro version only for it to ask my again to purchase it. 

Even tried to close the app and open again still nothing.

### 1/5 — Glitchy. Doesn’t work.

*2022-02-28*

I actually paid for the pro version and it wouldn’t switch over from the basic app. I never received the access that I purchased. When trying to send an email under the “send feedback” button, the email wouldn’t go through. This is extremely glitchy and a waste of money.

## Frequently asked questions about 1RM Calculator

### What is a 1RM Calculator?

A 1RM Calculator is a utility that estimates the maximum weight you can lift for a single repetition. You input the weight you successfully lifted and the number of repetitions you performed, and the app calculates your estimated one-rep max.

### How does this app help with strength training?

It helps you gauge your current strength levels and track your progress over time. By comparing different lifts and rep schemes, you can better understand your strength gains and plan future training sessions more effectively.

### What features are available in the Pro version?

The Pro version offers an ad-free experience, the ability to save and track your lift history, historical chart and list views categorized by exercise, more estimation formulas, calculation of multiple rep maxes, unit switching (lbs/kgs), and a percentage view of your 1-rep max.

### Is this app compatible with both pounds and kilograms?

Yes, the Pro version of the app allows you to switch between pounds (lbs) and kilograms (kgs) for your weight entries and calculations, making it suitable for users worldwide.

### How accurate are the 1RM estimates?

The app provides estimates based on the data you enter. These calculated values may vary from actual measured values. It's important to always use a spotter and warm up adequately when attempting to find your true maximum lift to prevent injuries.

## Version history (last 5 releases)

### 4.5 — 2019-05-20

- Ability to export your data in a CSV file (PRO)
- Minor UI enhancements

### 4.4 — 2019-05-13

- Minor UI improvements and bug fixes

### 4.3 — 2019-05-01

- Minor UI improvements

### 4.2 — 2019-04-30

- UI enhancements and improvements
- Exercise selector and ability to add new exercises
- Ability to save your progress and log your 1RM entries [PRO]
- Historical chart and list views, categorized by exercise [PRO]

### 4.1 — 2019-03-31

Minor UI improvements

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## More apps by David Bai

- [Hatch Squat Program](https://appshunter.io/ios/app/hatch-squat-program/id1301427885)
- [Smolov Squat Program](https://appshunter.io/ios/app/smolov-squat-program/id1315546492)
- [Random WOD Generator](https://appshunter.io/ios/app/random-wod-generator/id1456533132)
- [Watchtimes - Watch Tracker](https://appshunter.io/ios/app/watchtimes-watch-tracker/id1500152333)

All apps by David Bai: https://appshunter.io/developer/609405595

## Related topics

[1rm calculator](https://appshunter.io/ios/topics/1rm-calculator) · [1rm](https://appshunter.io/ios/topics/1rm) · [one rep max](https://appshunter.io/ios/topics/one-rep-max) · [one rep max calculator](https://appshunter.io/ios/topics/one-rep-max-calculator) · [1rm max calculator](https://appshunter.io/ios/topics/1rm-max-calculator) · [my one rep max](https://appshunter.io/ios/topics/my-one-rep-max) · [the one rep max](https://appshunter.io/ios/topics/the-one-rep-max) · [max rep calculator](https://appshunter.io/ios/topics/max-rep-calculator) · [rep max calculator](https://appshunter.io/ios/topics/rep-max-calculator) · [1rm weight lifting rep max](https://appshunter.io/ios/topics/1rm-weight-lifting-rep-max) · [rep calculator](https://appshunter.io/ios/topics/rep-calculator)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-04.*