Ratio Calc! vs LapMonitor
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Ratio Calc!
This app helps radio control car racers calculate their final drive ratio and rollout. Easily select your car, input gear sizes, and get instant results. It also offers charts and saves favorite cars for quick access.
- Calculate Final Drive Ratio (FDR)
- Calculate Rollout with tire diameter
- Filter cars by manufacturer and model
- Save favorite cars
- Select measurement units (imperial/metric)
- Select gear pitch
- View ratio and rollout charts
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Ratio Calc is a quick and easy tool for radio control car racers to use trackside. Knowing your final drive ratio (FDR) is very useful for comparison with other racers to determine if your car is geared correctly. It lets you quickly select your car by filtering on manufacturer and model. Select your pinion and spur size and the FDR is displayed. Tyre diameter can also be entered to calculate your rollout. Ratio and roll out charts are also available which plot pinion and spur gear combinations to create very handy reference tables. - Save your favourite cars for quick access - Select measurement units (imperial/metric) - Select your preferred gear pitch, alternative ratios in other pitches will be shown - Over 2000 cars/variants in the database which is updated regularly
LapMonitor
This application pairs with a dedicated device to provide real-time lap timing for RC car races. It supports single or multi-racer configurations, displays live rankings and race data, and announces key events. Race history is automatically saved and can be exported or shared.
- Bluetooth device connection
- Multi-driver race configuration
- Real-time driver ranking
- Speech synthesis for race events
- Detailed lap information
- Automatic race data saving
- Race data export and sharing
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LapMonitor is the companion application of the LapMonitor device, the best lap counter for RC cars. It allows single racer lap timing or multi-racers. It includes the following features: - Connect to a LapMonitor device over Bluetooth; - Configure and start a multi-drivers race; - Display the driver ranking and race data in real-time (number of laps, last lap, best lap…); - Use speech synthesis to announce important race events; - Display detailed laps information for any driver in the race; - Automatically save race data on your device, and you can view the race details later in the Session History screen; - Export race data as a text file; - Share race data with your friend by email, Twitter, cloud file services…
Screenshots
Verdict
The clearest difference is rating: LapMonitor at 5.0 against Ratio Calc!'s 4.5. LapMonitor also leads on in-app purchases (none vs 4) and review sentiment (100% vs 88%). Ratio Calc!'s advantage is update cadence (every 4 months vs every 9 months). On price, ratings volume, ads and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Ratio Calc! sells 4 one-off in-app purchases. LapMonitor asks for nothing beyond the download.
LapMonitor holds the better App Store score, 5.0 against 4.5. Both are backed by a comparable volume of ratings — 25 and 13 respectively. Written reviews point the same way: 88% of Ratio Calc!'s written reviews are positive against 100% of LapMonitor's.
Ratio Calc! ships an update every 4 months, LapMonitor every 9 months. The most recent releases landed on October 16, 2026 and October 7, 2026 respectively.
| Parameter | Ratio Calc! | LapMonitor |
|---|---|---|
| Price | Free | Free |
| Rating | 4.5 (25 ratings) | 5.0 (13 ratings) — better |
| Positive reviews | 87.5% of reviews | 100.0% of reviews — better |
| Number of ratings | 25 — better | 13 |
| Update frequency | Every 4 months — better | Every 9 months |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 17.0 | 12.0 — better |
| Further details — not scored | ||
| Size | 69 MB | 17 MB |
| Age rating | 4+ | 4+ |
| Developer | David Mills | GY FX |
Customer experience
Ratio Calc!
LapMonitor
Bugs and requests
Ratio Calc!
Reported bugs
5 issues- Cannot adjust tyre sizes in latest version
- Cannot adjust gear ratio in latest version
- Bug on iPad: 'done' button missing after setting pinion/spur
- Removed notes feature in latest update
- Removed ability to save same vehicle twice in latest update
Requested features
13 requests- Add Mod 1 pinions and spurs
- Add support for 1:8 e-buggies
- Reintroduce notes feature
- Reintroduce ability to save same vehicle twice
- Add iCloud backup or import/export feature
Show 8 moreShow fewer
- Add option to attach setup sheets/track data
- Add input for battery used and motor specs
- Add speed chart for comparison
- Allow selection of gear pitch for each car
- Update app to include new kits
- Add more car models
- Divide Asphalt into 1:12 and 1:10 categories
- Add watch app
LapMonitor
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Ratio Calc!
- Nice Tip$0.99
- Generous Tip$2.99
- Mega Tip$4.99
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- Insane Tip$9.99
LapMonitor
No in-app purchases
Questions
Is Ratio Calc! free?
Is LapMonitor free?
Which has better reviews, Ratio Calc! or LapMonitor?
Do Ratio Calc! or LapMonitor have ads?
Which is updated more often, Ratio Calc! or LapMonitor?
Other comparisons
