TradeCalc Support

Pick a trade, choose a calculator, and enter your numbers. Results update as you type, and every calculator shows both the materials you need and the cost to buy them. The feet, inches and fractions calculator, Ohm's Law and square footage are free; any purchase unlocks the rest.

Check your inputs and units first. Most calculators depend on a unit setting (for example feet versus meters, or inches versus millimeters) and on values like density, waste factor or price that you can adjust. Make sure each field matches what you intended, including any waste or rounding factor, then re-check the result.

For electrical, plumbing and HVAC calculators, confirm you have selected the correct material, conductor or duct type, since those change the output.

TradeCalc is built to run fully offline. You do not need a signal or a network connection for any calculator. If the app ever seems stuck, fully close it and reopen it; nothing depends on a server because there is no server.

If you reinstall the app or switch devices, open the paywall or settings and tap "Restore Purchases" to bring back your Lifetime unlock or active subscription. Make sure you are signed in with the same Apple ID you purchased with.

Subscriptions are billed through Apple, not by us. Manage or cancel anytime in your Apple ID subscription settings: open the iOS Settings app, tap your name, tap Subscriptions, then select TradeCalc.

Cancel at least 24 hours before the end of the current period to avoid the next charge. The weekly plan includes a 3-day free trial; cancelling during the trial means you are never charged. The Lifetime option is a one-time purchase with nothing to renew or cancel.

Refunds are handled by Apple under App Store policy: request one at reportaproblem.apple.com.

The app is 100% offline and collects no data at all: no account, no analytics, no ads, no tracking. See the Privacy Policy.

Email info@appharbour.com. Include your iOS version, which calculator you were using and a short description of the issue, and we will get back to you as soon as we can.