Time Duration Arithmetic Calculator ← Calculator LibraryUnits and practical toolsTime Duration Arithmetic CalculatorAdd or subtract nonnegative durations in hours, minutes and seconds. StyleModernVintageRetro First duration H:MM:SS OperationAddSubtract Second duration H:MM:SS Calculate & explainReset example Durations, not clock times or time zones. Your original main Hours calculator remains unchanged. Open Dual Calculators → Want more practice? The CalculatorWiser MAX Member Library includes up to 1,500 printable resources, answer keys, favorites and progress tracking. Compare membership levels → Share this page Share Facebook X LinkedIn Reddit Pinterest WhatsApp Telegram Threads Bluesky Tumblr Email Text Copy link Save this math resource for laterSave to Pinterest