Comparison

coolAltitude vs Q400

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

coolAltitude

This app provides pilots with essential tools for cold-temperature altitude corrections, approach profiles, and de-icing calculations. It integrates weather data and offers a clear interface for critical flight planning information.

Highlights
  • Cold-temperature altitude corrections
  • Approach profile visualization
  • De-icing and holdover time calculations
  • FMS-style approach setup
  • METAR, TAF, and runway condition integration
  • Light and dark mode support
Features
Read full description

coolAltitude brings cold-temperature altitude corrections, approach profiles and de-icing tools into one focused workspace for pilots. ALTITUDE CORRECTIONS Enter the temperature and approach data, compare entered and corrected altitudes, and see the result in a clear approach profile. Select the correction method and rounding option for your workflow. DME shift helps put distance references in context. APPROACH SETUP Use the FMS-style interface to work with airport, runway and approach data. A structured display and dedicated keys keep the setup readable alongside the profile. DE-ICING AND HOLDOVER TIME Select the applicable conditions, fluid type and concentration. Review the available holdover guidance and keep the countdown visible during your workflow. WEATHER AND RUNWAY CONTEXT Consult METAR, TAF and runway-condition information alongside your calculations. Online information depends on the availability of the connected services. READABLE IN LIGHT AND DARK Clear colour roles distinguish inputs, corrected values and shifted values. Light and Dark appearances support different lighting conditions, with restrained surfaces and readable controls. Some features require an in-app subscription. Check the in-app purchase screen for the features included, subscription terms and current pricing. Use current operational information and the procedures applicable to your aircraft and operation when assessing results. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

Q400

Features
Read full description

Fast, accurate takeoff and landing performance for the DHC-8-402 (Q400) — 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 — no paper charts, no guesswork. KEY FEATURES • Takeoff — V1/VR/V2, max weights and limit codes for dry, wet, tailwind, MEL and contaminated runway conditions • Reduced (assumed-temperature) takeoff with torque selection • Landing — Vref, Vtarget, Vmax, go-around speeds with wind and contamination corrections • Cruise — LRC, ISC, HSC, MCR plus single-engine and holding performance • Missed approach climb gradients • De-icing / icing speed corrections applied automatically • Built-in airport and runway database — 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 — no account required, no personal data collected, no tracking. Calculate with confidence. Download Q400 Performance Calculator today.

Screenshots

coolAltitude4 screens
Q4004 screens

Verdict

The call

The clearest difference is price: Q400 at Free against coolAltitude's $7.99. On update cadence, ads, in-app purchases 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

CostPrice · In-app purchases · Ads · Monetization

Q400 is free to download; coolAltitude costs $7.99 up front. coolAltitude sells 2 in-app purchases, starting at $7.99 per year 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.

UpkeepUpdate frequency

coolAltitude ships an update every 3 months, Q400 every 5 months. The most recent releases landed on November 7, 2026 and November 9, 2026 respectively.

Scorecard1 real difference · 9 level
coolAltitude versus Q400: the parameters behind the verdict, then further details
ParametercoolAltitudeQ400
Price$7.99Free — better
Rating5.0 (7 ratings) — better—
Positive reviews60.0% of reviews—
Number of ratings7 — better—
Update frequencyEvery 3 months — betterEvery 5 months
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchases—
DevicesiPhone, iPadiPhone, iPad
Requires iOS17.0 — better18.6
Further details — not scored
Size56 MB10 MB
Age rating17+4+
DeveloperSilkIdea s.r.o.MacLaren's Studio

In-app purchases

2 purchases

coolAltitude

Subscriptions2
  • De & Anti-Icing Pro$7.991 Year
  • Save & Retrieve Approach Data$7.991 Year
2 purchases

Q400

Subscriptions2
  • Monthly7 Days trial$4.991 Month
  • Annual7 Days trial$29.991 Year

Questions

Is coolAltitude free?
coolAltitude costs $7.99, and also offers in-app purchases.
Is Q400 free?
Q400 is free to download, with in-app purchases available.
Do coolAltitude or Q400 have ads?
Neither coolAltitude nor Q400 shows ads.
Which is updated more often, coolAltitude or Q400?
coolAltitude ships an update every 3 months, and Q400 every 5 months. Most recently, coolAltitude was updated on November 7, 2026 and Q400 on November 9, 2026.

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