Rate calculator
Crash rate calculator
Type a crash count and a population and get the rate per 100,000 residents. Add vehicle-miles for the rate per 100 million miles. Every step of the arithmetic is printed under the result, worked on your numbers.
United States, 2024 (example)
10.7 crashes per 100,000 residents, and 1.1 per 100 million vehicle-miles. For comparison, the United States recorded 10.7 fatal crashes per 100,000 residents and 1.1 per 100 million miles in 2024. That comparison only holds if your count is fatal crashes too.
The road is a scale from 0 to 40 per 100,000. The yellow post is your rate; the white post is the US fatal crash rate in 2024. A rate above 40 sits at the end of the road.
- Formula
- crashes ÷ (residents × years) × 100,000
- Worked
- 36,297 ÷ (340,003,797 × 1) × 100,000 = 36,297 ÷ 340,003,797 × 100,000 = 10.7
- Per mile
- crashes ÷ (million vehicle-miles × 1,000,000 × years) × 100,000,000
- Worked
- 36,297 ÷ (3,294,031 million × 1) × 100 = 1.1
- One crash
- 100,000 ÷ 340,003,797 = 0 points per crash
How the rate is calculated
- Per 100,000 residents: crashes ÷ population × 100,000. For a count that spans several years, the denominator is population × years (resident-years), which gives the annual rate the federal safety rule calls a five-year rolling average. It is the form news stories and public-health tables use.
- Per 100 million vehicle-miles: crashes ÷ vehicle-miles × 100,000,000, the form in 23 CFR 490.207. It adjusts for how much people drive. FHWA’s Highway Statistics table VM-2 publishes vehicle-miles by state in millions, which is why the box takes millions; there are no county figures.
- Where to get the inputs: fatal crash counts for any county or state are on this site’s county lookup, from NHTSA’s FARS; populations from the Census Bureau’s county estimates. Counts of all police-reported crashes come from state DOT crash files, which differ in what they record.
- What a rate cannot say: it measures how often crashes happened in a place relative to the people who live there or the miles driven there. It is not the risk to any one driver, road or trip, and a count from one record cannot be compared with a rate from another.
Informational only, not professional advice. Last reviewed: October 2026. Example figures from the 2024 snapshot built 2026-10-30.
Frequently asked questions
How do I calculate a crash rate per 100,000?
Divide the number of crashes by the population of the place, then multiply by 100,000. If the count covers more than one year, divide by the population multiplied by the number of years (resident-years) so the result is an annual rate. The calculator does exactly this and prints the arithmetic.
How do I calculate a crash rate per 100 million vehicle-miles?
Divide the number of crashes by the vehicle-miles travelled in the same place and period, then multiply by 100,000,000. FHWA publishes vehicle-miles by state in millions, so the calculator takes millions and multiplies by 1,000,000 first. This is the form federal highway safety performance rules use (23 CFR 490.207).
Does the count have to be fatal crashes?
No. The arithmetic is the same for any count: fatal crashes, injury crashes, all police-reported crashes. What matters is saying which record the count came from. CrashRate's own pages use fatal crashes only, from NHTSA FARS, because it is the one public record coded to every county.
Why does one crash move a small town's rate so much?
A rate per 100,000 scales the count up by 100,000 divided by the population. With 5,000 residents, one crash is 20 points. The calculator prints that step so a rate for a small place can be read with its count beside it. Federal rules use a five-year count for the same reason.
Related tools
Type a county and see its fatal crash rate: NHTSA fatal crashes divided by Census population, per 100,000, with every input shown. State pages add the rate per 100 million miles.
Open tool →Compare Fatal Crash Rates of Two StatesTwo states side by side: NHTSA fatal crashes per 100,000 residents and per 100 million vehicle-miles, the five-year average and what the record says about those crashes. No ranking.
Open tool →