Hour Calculator – Add, Subtract & Calculate Total Hours

Calculate hours across shifts, projects, and schedules with precision. Add multiple time entries, subtract hours from totals, and convert between hours and minutes. Essential for payroll, time tracking, and project management.

What Is an Hour Calculator?

An hour calculator performs arithmetic on hour-based time values. It adds hours across multiple entries, subtracts time from totals, and handles the complexities of time math—like carrying 60 minutes into hours automatically.

Features

How to Use This Tool

Adding Hours

1. Enter your first time entry (hours and minutes)
2. Add more entries as needed
3. View the running total automatically

Subtracting Hours

1. Enter your starting total (e.g., 40 hours)
2. Enter time to subtract (e.g., worked hours)
3. View the remaining balance

Converting Time

Use the tool to convert between formats:

• 1.5 hours = 1 hour 30 minutes
• 90 minutes = 1 hour 30 minutes

Common Use Cases

Payroll & Timesheets

Track employee hours across pay periods:

Project Tracking

Calculate time spent on tasks:

• Research: 4h 30m
• Design: 6h 15m
• Development: 12h 45m
• Testing: 3h 30m
• Project Total: 27h 00m

Overtime Calculation

Calculate hours over the regular threshold:

• Total worked: 47h 30m
• Regular hours: 40h 00m
• Overtime: 7h 30m

Freelance Billing

Track billable hours for clients:

• Client A: 12h 15m
• Client B: 8h 45m
• Client C: 15h 30m
• Total billable: 36h 30m

Academic Study Tracking

Monitor study time across subjects:

• Math: 5h 00m
• Science: 4h 30m
• English: 3h 45m
• History: 2h 15m
• Weekly total: 15h 30m

Hour-Minute Conversion Reference

Minute to Decimal Conversion

Frequently Asked Questions

How do I round hours for billing?

Common rounding methods:

• 6-minute increments (0.1 hour) — Legal billing standard
• 15-minute increments (0.25 hour) — Common for freelancers
• 30-minute increments — For simple tracking

Can I enter time in decimal format?

Depending on the tool mode, enter 1.5 for 1 hour 30 minutes, or use separate hour/minute fields.

What about seconds?

This tool focuses on hours and minutes. For second-precision, use our Time Calculator.

How do I handle overnight shifts?

For shifts crossing midnight, calculate each day separately or treat as one continuous duration.

Can negative hours result?

If you subtract more than the available total, you'll see the "negative" remainder (debt/overtime depending on context).

Is there a maximum hours limit?

No practical limit—calculate totals of thousands of hours if needed.

Format Guidelines

Entering Time

• 1h 30m — One hour thirty minutes
• 1:30 — Same as above
• 1.5 — Decimal hours (1.5 = 1h 30m)
• 90m — Ninety minutes (= 1h 30m)

Reading Results

Results are displayed in the clearest format for your context, typically as "Xh Ym" or "X:YY".

Pro Tips

1. Group by category — Calculate subtotals for different project types
2. Round consistently — Pick a rounding method and stick to it
3. Track daily — Enter hours as you work, not at week's end
4. Include breaks — Don't forget to subtract unpaid break time
5. Save totals — Keep records for payroll and tax purposes

Industry Standards

Related Tools

Explore more time and calculation utilities:

• Time Calculator — Full time math with seconds
• Timezone Converter — Convert time zones
• Date Calculator — Days between dates
• Percentage Calculator — Percent calculations
• Average Calculator — Mean calculations

Calculate hours above for timesheets, project tracking, payroll, and any hour-based calculations. Handles hours and minutes with automatic conversions.