Date Difference Calculator
Find the number of days, weeks, and hours between two dates. Free date difference calculator.
How to use this date difference calculator
Project plans, travel, and statutes of limitation all count days. Enter a start and end date to get elapsed days, weeks, and hours. This is a calendar span, not a business-day counter.
Formula
Worked example
January 1 to January 8 is 7 elapsed days.
Related calculators
More everyday calculators
- Rent Increase Calculator — Turn a rent hike into new monthly rent, percent increase, and extra cost per year. Enter a percent or a dollar increase for tenants and landlords.
- TV Size / Viewing Distance Calculator — Convert seating distance to a recommended 4K TV diagonal, or a TV size to a viewing distance. Uses ~30° cinematic angle rules of thumb.
- Tire Size Difference Calculator — Compare two tire sizes (width / aspect / rim). See diameter, circumference, plus speedometer error if you change overall height.
- Gas Trip Cost Calculator — Estimate fuel cost for a road trip from miles, MPG, and price per gallon. Optional round trip and split among passengers.
- Sleep Calculator — Find bedtimes from a wake-up time, or wake times from a bedtime, using 90-minute sleep cycles plus time to fall asleep.
- Caffeine Half-Life Calculator — See how much caffeine is still in your system and when it will wear down to a quarter-cup or nearly gone. Default adult half-life is 5 hours.
Frequently asked questions
Is this date difference calculator free?
Yes. It works instantly in your browser with no signup.
Are the results exact?
Results follow the stated formula, but real-world fees, timing, and rounding can vary.
How do I find the number of days between two dates?
This tool takes the absolute difference in calendar days. January 1 to January 8 is 7 elapsed days.
Does it include the end date?
It counts the span between the dates (end minus start), not a fully inclusive stay unless the dates are the same.
Business days vs calendar days?
This is calendar days, including weekends and holidays. It does not skip non-work days.
Can I get weeks and hours?
Yes. The breakdown shows weeks (days ÷ 7) and hours (days × 24).
Results are estimates for informational purposes and are not financial, legal, or professional advice. Last reviewed 2026-08-20.