# MyRPMCalc — Engine RPM From Sound

> Acoustic engine RPM measurement tool using smartphone microphone. (iPhone/iPad app by C&S Industries, LLC.)

- Source: https://appshunter.io/ios/app/myrpmcalc/id6792172193 (this page in markdown: same URL + `.md`)
- Developer: [C&S Industries, LLC](https://appshunter.io/developer/6785223876)
- Category: Productivity, Utilities
- Price: $1.99
- Age rating: 4+
- Requires: iOS 17.0 · 3 MB
- Languages: American English
- Released: 2026-07-31
- Data updated: 2026-08-26
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/myrpmcalc/id6792172193/reviews.md

## What is MyRPMCalc?

Point your phone at a running engine and read its RPM instantly — no OBD adapter, no clip-on inductive sensor, no wiring. RPMCalc listens through your microphone and calculates engine speed straight from the sound of the exhaust or the engine itself.

HOW IT WORKS
Every engine's exhaust note has a fundamental firing frequency set by its cylinder count, stroke cycle, and RPM. RPMCalc analyzes that frequency in real time and converts it to a live RPM reading — accurate to the nearest 1 RPM on the digital readout, with a classic analog tachometer dial for an at-a-glance feel.

BUILT FOR ANY ENGINE
- Set any cylinder count from 1 to 12
- Choose 2-stroke or 4-stroke cycle
- Works on cars, motorcycles, lawn mowers, generators, chainsaws, go-karts, boats, and other small engines

WORK ALONE, HANDS-FREE
Diagnosing an engine is usually a two-person job — one to rev it, one to watch the gauge. RPMCalc's Auto-Freeze feature fixes that. Set a delay (5 to 30 seconds), tap Start Listening, prop the phone near the exhaust, and walk to the driver's seat. RPMCalc automatically freezes the reading after your chosen delay so it's waiting for you, unchanged, when you walk back. A manual Freeze/Resume button is also there any time you want to hold a reading on the spot.

SIMPLE, FOCUSED, NO CLUTTER
One screen. No accounts, no ads, no subscriptions, no clutter. Just a tachometer, a couple of settings, and a listen button.

PRIVACY
RPMCalc processes audio entirely on your device. Nothing is recorded, uploaded, or shared.

PLEASE NOTE
RPMCalc estimates engine speed acoustically and is not a certified or calibrated tachometer. Background noise, wind, and exhaust modifications can affect accuracy. Don't rely on it as the sole basis for safety-critical decisions like redline limits or tuning — always follow your engine or equipment manufacturer's official guidance.

## Key features

- Instant RPM reading from sound
- No OBD adapter or sensors required
- Supports 1-12 cylinders
- 2-stroke or 4-stroke cycle selection
- Auto-Freeze for hands-free use
- Manual Freeze/Resume button

## Chart rankings

- #200 in Top Paid · Productivity (US App Store)

## Recent user reviews (1 of 1)

All indexed reviews: https://appshunter.io/ios/app/myrpmcalc/id6792172193/reviews.md

### 1/5 — Please return my money

*2026-08-11*

This app shows an rpm reading when there is complete silence… useless at best, inaccurate out of the box…

## Frequently asked questions about MyRPMCalc

### How does MyRPMCalc measure engine RPM?

MyRPMCalc analyzes the fundamental firing frequency of an engine's sound through your phone's microphone. It calculates the RPM based on this acoustic analysis, providing a live reading.

### What types of engines does MyRPMCalc work with?

MyRPMCalc is designed to work with a wide range of engines, including cars, motorcycles, lawn mowers, generators, chainsaws, go-karts, and boats. It supports engines with 1 to 12 cylinders and both 2-stroke and 4-stroke cycles.

### Can I use MyRPMCalc by myself to check RPM?

Yes, MyRPMCalc features an Auto-Freeze function that allows for hands-free operation. You can set a delay for the reading to freeze, enabling you to rev the engine and then check the RPM without needing a second person.

### Is MyRPMCalc accurate for critical engine tuning?

MyRPMCalc provides an estimate of engine speed acoustically and is not a certified or calibrated tachometer. Factors like background noise and exhaust modifications can affect accuracy. Always refer to official manufacturer guidance for safety-critical decisions.

### Does MyRPMCalc have ads or subscriptions?

No, MyRPMCalc is designed to be simple and clutter-free. It does not contain any advertisements, subscriptions, or require accounts for use.

### What devices does MyRPMCalc support?

MyRPMCalc is currently available for iPhone devices. The app processes audio entirely on your device for privacy.

### How often is MyRPMCalc updated?

MyRPMCalc was last updated on July 31, 2026, with version 1.0. Future updates will likely focus on improving accuracy and compatibility based on user feedback.

### What is the price of MyRPMCalc?

MyRPMCalc is a paid application priced at $1.99. This one-time purchase grants you full access to all its features without any ads or in-app purchases.

## Version history (last 1 release)

### 1.0 — 2026-07-31

No release notes.

## More apps by C&S Industries, LLC

- [LevelUP Tool](https://appshunter.io/ios/app/levelup-tool/id6789370286)
- [GhostAlias](https://appshunter.io/ios/app/ghostalias/id6796787217)
- [MOACalc for Shooters](https://appshunter.io/ios/app/moacalc-for-shooters/id6796809150)

All apps by C&S Industries, LLC: https://appshunter.io/developer/6785223876

## Related topics

[rpm go](https://appshunter.io/ios/topics/rpm-go)

---

*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 2026-08-26.*