Rafter Help vs Slope Calculator
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Rafter Help
This app simplifies roof construction by calculating rafter lengths and related measurements. It supports various input formats for pitch and length, offering both quick calculations for gable roofs and advanced control for more complex needs.
- Calculate rafter length and associated values
- Determine roof pitch, rafter lengths, and ridge height
- Supports gable roofs
- Advanced calculation options
- Multiple input formats for pitch (radians, degrees, DMS, rise/run)
- Flexible length units (mm, cm, inches, feet)
- Customizable decimal places
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Rafter Help is the easiest way to calculate rafter length and associated values when building! Quickly find roof pitch, rafter lengths and ridge height for gable roofs, based on room and ridge width. Or calculate length values with more control from the Advanced tab. Features Include: - Accurately solve rafter equations - Enter pitch steepness in radians, decimal degrees or degrees, minutes, seconds (DMS) or rise/run (e.g. 8/12) - Enter lengths in mm, cm, inches or feet - Select your preferred number of decimal places
Slope Calculator
Calculate slope in angle, percentage, or ratio by inputting two sides of a right triangle. This intuitive and easy-to-use application provides the remaining necessary values.
- Calculate slope as angle
- Calculate slope as percentage
- Calculate slope as ratio
- Input two sides of a right triangle
- Calculate remaining triangle values
- Intuitive and easy to use
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Use this App to calculate slope (Angle, Percentage, Ratio). You just need to enter 2 of the 3 sides of a right triangle, we will calculate for you the remaining necessary numbers. This is a very intuitive App, simple and easy to use. Results are estimates for informational purposes only. We are very happy to serve you. If you have any requests, don't hesitate to contact us. - https://www.facebook.com/phan.nhatdang.3/ - phannhatd@gmail.com
Screenshots
Verdict
The clearest difference is price: Slope Calculator at Free against Rafter Help's $1.99. Slope Calculator also leads on review sentiment (58% vs 40%). Rafter Help's advantage is in-app purchases (none vs 1) and update cadence (every 5 months vs every 14 months). On rating, 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
Slope Calculator is free to download; Rafter Help costs $1.99 up front. Slope Calculator sells 1 one-off in-app purchase. Rafter Help asks for nothing beyond the download.
Rafter Help holds the better App Store score, 4.5 against 4.3. Both are backed by a comparable volume of ratings — 214 and 104 respectively. Written reviews complicate that: 40% of Rafter Help's written reviews are positive against 58% of Slope Calculator's, so the app with the better star average is not the one people write more warmly about.
Rafter Help ships an update every 5 months, Slope Calculator every 14 months. The most recent releases landed on October 26, 2026 and October 23, 2026 respectively.
| Parameter | Rafter Help | Slope Calculator |
|---|---|---|
| Price | $1.99 | Free — better |
| Rating | 4.5 (214 ratings) — better | 4.3 (104 ratings) |
| Positive reviews | 40.0% of reviews | 58.3% of reviews — better |
| Number of ratings | 214 — better | 104 |
| Update frequency | Every 5 months — better | Every 14 months |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 10.0 — better | 13.0 |
| Further details — not scored | ||
| Size | 6 MB | 5 MB |
| Age rating | 4+ | 4+ |
| Developer | Armchair Engineering | Phan Nhat Đang |
Customer experience
Rafter Help
Slope Calculator
Bugs and requests
Rafter Help
Reported bugs
4 issues- Cannot add 1/4 inch
- Missing decimal point on keypad
- Major error in basic gable drawing
- App won't open, says 'waiting'
Requested features
8 requests- Add 1/4 inch input
- Provide cut angles
- Include decimal point on keypad
- Support hip rafters
- Correct drawing error for basic gable
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- Include HAP calculation
- Include rafter width
- Accept angles in degrees and pitch-in-12
Slope Calculator
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Rafter Help
No in-app purchases
Slope Calculator
- Remove ads$1.99
Questions
Is Rafter Help free?
Is Slope Calculator free?
Which has better reviews, Rafter Help or Slope Calculator?
Do Rafter Help or Slope Calculator have ads?
Which is updated more often, Rafter Help or Slope Calculator?
Other comparisons
