The straight-line distance and the driving distance are two different numbers, and Google Maps gives you them separately. The straight line, as the crow flies, comes from “Measure distance”; the road distance, from “Directions”. If you want both at once and how much longer the drive is, the straight line vs driving distance tool works them out in one go. Here are the Google Maps steps, an example with real numbers and a table of detours between US cities.
Both distances in Google Maps
As the crow flies, on a computer:
- Open Google Maps and right-click your starting point.
- Choose Measure distance.
- Click your destination. The total distance shows at the bottom, in miles and kilometers.
Google’s own help gives this as an example: you can measure the mileage in a straight line between two cities. For the phone version, see the guide to measuring on Google Maps.
By road:
- Click Directions.
- Enter your start and destination, or click points on the map.
- Click the Driving icon. Each route shows its estimated travel time; the best is blue and the alternatives gray.
That’s two separate lookups, and the ratio between them is up to you.
In one step, with the detour worked out
- Open straight line vs driving distance.
- Enter the two places in From (A) and To (B), paste coordinates or tap the map.
- The straight line appears right away; the road distance follows a second later, with the route drawn in green. Below, you’ll see how many miles the road adds, as a percentage, and the detour factor.
- Cycling or walking? Switch the travel mode and the route is worked out again.
An example: Denver to Grand Junction
Using each city’s point from the Census Bureau’s Gazetteer Files:
- As the crow flies: 203 miles.
- By road: 254 miles, about 4 h 52 min.
- Detour: 50.9 extra miles, 25% more (factor 1.25).
The road has to cross the Rocky Mountains through valleys and passes instead of going straight over them. That’s exactly when the straight line is misleading.
How much longer the drive is between US cities
Measured with the same routing service, between each city’s point in the Census Gazetteer Files, on October 31, 2026:
| Trip | Straight line | By road | Detour |
|---|---|---|---|
| Dallas – Houston | 222.7 mi | 238.2 mi | 7% |
| New York City – Los Angeles | 2,464 mi | 2,811 mi | 14% |
| Chicago – Detroit | 238.5 mi | 277.3 mi | 16% |
| Los Angeles – Las Vegas | 234.6 mi | 290.7 mi | 24% |
| Denver – Grand Junction | 202.6 mi | 253.5 mi | 25% |
| Salt Lake City – Denver | 379.0 mi | 523.7 mi | 38% |
| San Francisco – Oakland | 10.0 mi | 14.3 mi | 43% |
| Seattle – Port Angeles | 61.6 mi | 140.0 mi | 127% |
In this table, the most direct trips add between 7% and 16%. Mountains push it past 20%, and water does the most damage: Seattle to Port Angeles is more than twice as long by road, because the route heads south through Tacoma to get around Puget Sound. On short trips like San Francisco to Oakland, a few extra miles already make a big percentage.
Why roads take detours
- Terrain. Roads follow valleys and cross mountain ranges at passes, with curves to keep the grade gentle.
- Water. A bay, a lake or a river with no bridge nearby forces you to go around.
- The network. Between two small towns there may be no direct road, so you drive out to the interstate even if it’s out of the way.
- The fastest route isn’t the shortest. It often pays to add a few miles on the interstate, and Mapsfera, like a navigation app, gives you the fastest one.
Which distance to use
- For a trip, gas or travel time: the driving distance.
- For a radius or a service area (“within 50 miles of”): the straight line. To draw one, see the guide to drawing a radius.
- For “how far can I get in 30 minutes?”: neither; you want a drive time map, explained in the drive time map guide.
- To meet halfway: the point where you both drive the same time, explained in the halfway point guide.
Keep in mind that the distance between two cities depends on the point you pick for each. Mapsfera uses each city’s point from the Census Bureau’s Gazetteer Files; Google uses its own. Two sites can disagree by a few miles without either being wrong. For many pairs at once, the distance matrix works out every combination.