GroundRollCalc vs Q400
Price, ratings, monetisation and update history for both apps, side by side β with what reviewers say about each.
GroundRollCalc
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Key Features Ground Roll Estimation Calculates expected takeoff ground roll based on: - Aircraft performance data - Weight and loading - Wind conditions - Density altitude - Runway slope and surface - Runway Visualization Graphical runway display with: - Estimated ground roll marker - Safety margin indicators - Remaining runway awareness Live GPS Mode (Optional) - Track actual takeoff roll in real time - Compare real-world performance to predicted values - Detect deviations from expected performance Aircraft & Airport Management - Store multiple aircraft profiles - Manage airport and runway data - Customize inputs for accurate calculations Built for Real-World Flying - Designed for clarity and speed in the cockpit - Clean interface optimized for iPad use - Focused on practical, decision-support information Important: GroundRollCalc is a supplemental performance tool and is not a substitute for approved aircraft performance data, POH/AFM guidance, or pilot judgment. Always verify performance calculations and operate in accordance with safe aviation practices. Data Sources Airport and aeronautical data may include publicly available datasets such as FAA and openAIP sources. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Q400
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Fast, accurate takeoff and landing performance for the DHC-8-402 (Q400) β built by pilots, for pilots. Q400 Performance Calculator turns AFM tables into instant results on the flight deck. Enter your conditions and get V-speeds, weight limits, and runway-specific numbers in seconds β no paper charts, no guesswork. KEY FEATURES β’ Takeoff β V1/VR/V2, max weights and limit codes for dry, wet, tailwind, MEL and contaminated runway conditions β’ Reduced (assumed-temperature) takeoff with torque selection β’ Landing β Vref, Vtarget, Vmax, go-around speeds with wind and contamination corrections β’ Cruise β LRC, ISC, HSC, MCR plus single-engine and holding performance β’ Missed approach climb gradients β’ De-icing / icing speed corrections applied automatically β’ Built-in airport and runway database β elevation, length, slope, shift Designed around a clean cockpit-style interface: high-contrast values, dark display, and a layout that reads at a glance under any lighting. This app is a planning aid. Always cross-check results against the approved Aircraft Flight Manual and your operator's procedures. The pilot in command remains responsible for all performance decisions. SUBSCRIPTION Q400 Performance Calculator is available with a 7-day free trial, then $5/month or $30/year. Your subscription unlocks all calculators and runway data. Payment is charged to your Apple ID and auto-renews unless cancelled at least 24 hours before the end of the current period. Terms of Use (EULA): https://starbuck-dev.github.io/Q400Performance/terms/ Privacy Policy: https://starbuck-dev.github.io/Q400Performance/privacy/ Privacy first β no account required, no personal data collected, no tracking. Calculate with confidence. Download Q400 Performance Calculator today.
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Verdict
The clearest difference is update cadence: GroundRollCalc at every 5 days against Q400's every 5 months. On price, ads, in-app purchases and device support there is nothing between them.
Scored on Price Β· Rating Β· Positive reviews Β· Number of ratings Β· Update frequency Β· Ads Β· In-app purchases Β· Monetization Β· Best chart rank Β· Devices Β· Requires iOS
Both are free to download. GroundRollCalc sells 3 in-app purchases, starting at $0.99 per month and Q400 sells 2 in-app purchases, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.
GroundRollCalc ships an update every 5 days, Q400 every 5 months. The most recent releases landed on November 8, 2026 and November 9, 2026 respectively.
| Parameter | GroundRollCalc | Q400 |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 5 days β better | Every 5 months |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 18.5 β better | 18.6 |
| Further details β not scored | ||
| Size | 185 MB | 10 MB |
| Age rating | 4+ | 4+ |
| Developer | Rob Honeycutt | MacLaren's Studio |
In-app purchases
GroundRollCalc
- GroundRollCalc Pro Monthly$0.991 Month
- GroundRollCalc Pro Yearly$9.991 Year
- Unlock Live GPS$5.99
Q400
- Monthly7 Days trial$4.991 Month
- Annual7 Days trial$29.991 Year
Questions
Is GroundRollCalc free?
Is Q400 free?
Do GroundRollCalc or Q400 have ads?
Which is updated more often, GroundRollCalc or Q400?
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