Hours Calculator

An hours calculator helps you measure, add, and convert time. It’s handy for time cards, timesheets, project tracking, and any situation where you want a clear duration in hours and minutes (or decimal hours).

This page includes several modes (tabs) so you can solve different “hours and minutes” problems:

• Time duration: calculate the time between a start and end time (optionally subtracting a break). Use “time only” for same-day durations, or “date and time” for multi-day spans.
• Sum hours: add multiple time periods together (useful for tracking time across sessions).
• Convert time: convert between seconds, minutes, hours, days, weeks, and years (years are approximate).
• Work hours: enter daily start/end times (and breaks) to total a week of work hours.
• Add hours / subtract hours: move forward or backward from a start time to find a finish time or a start time.

All calculations run locally in your browser. If you need a countdown with an alert instead, use the online timer.

Tips and settings to keep results consistent:

• Use the Now buttons to quickly fill in the current time.
• Add breaks in minutes to deduct non-working time.
• For conversions involving years, remember results use a 365‑day year approximation.

If you use hours calculator often, bookmark this page or pin it as a shortcut so it’s always one tap away. For the best experience, keep the tab open and interact with the controls once so your browser allows audio alerts, permission prompts, or full-screen mode when needed.

For presentations, classrooms, or a second monitor, try full-screen mode. It centers the tool and removes distractions, and the zoom buttons let you fit the display to your viewing distance.

Browsers can throttle timers in background tabs to save battery. These tools keep accurate time by calculating against a stable clock, so even if the UI updates less frequently, the underlying time stays correct when you return.

Many pages are preset links. Sharing the URL is the fastest way to open the same configuration on another device, whether that’s a timer duration, a specific alarm time, or a countdown to an event year.

Your preferences (like theme and alarm sound) are stored locally in your browser. There’s no login required, and nothing needs to be uploaded for the tools to work.

If you’re using the site in bright sunlight or at night, switch themes for better contrast. Large digits and simple controls are intentional so the tools stay readable on small screens and from a distance.

If you use hours calculator often, bookmark this page or pin it as a shortcut so it’s always one tap away. For the best experience, keep the tab open and interact with the controls once so your browser allows audio alerts, permission prompts, or full-screen mode when needed.