Drive vs Fly Break-Even Calculator
Compare driving and flying on time and cost
Drive vs fly — FAQs
What’s a sensible airport overhead to use?
For large hubs on busy travel days, a total of 150–210 minutes door-to-door per one-way flight is common once you include transfers, check-in, security, boarding, and the last mile. For small regional airports or very off-peak flights, 90–150 minutes may be more realistic.
Should I add tolls, parking, or rental car costs?
These vary too much to hard-code. A practical approach is to fold tolls and parking into fuel cost or add them to the airfare if they’re tied to flying (like airport parking or a rental at your destination). Keep everything in the same currency when you compare.
Why not use live flight times or fares?
Live data can be fragile and context-blind. Instead, this calculator uses a transparent 500 mph or 800 km/h cruise speed with your chosen overhead and lets you plug in the fares you actually see. That keeps the math fast, offline-friendly, and easy to sanity-check.
How do groups change the result?
Driving fuel cost is largely fixed for the vehicle, while airfare scales per person. As you add travelers, driving often becomes more attractive on cost, even when flying is faster. The per-person lines in the result card make it easy to see how the split changes for two, three, or five people.
How to use this drive vs fly break-even calculator
This drive vs fly break-even calculator is built for real-world trip planning where you care about two things: what you spend and how long the trip actually takes door-to-door. Instead of juggling tabs, rough mental math, and fuzzy “it’s probably faster to fly” assumptions, you plug in a few basics and get a clear recommendation with the time and money trade-offs spelled out.
1. Pick your units and group size
Start by choosing whether you want to work in US units (miles, mph, mpg, $/gal), which are selected by default, or metric units (km, km/h, L/100 km, price per liter). Then enter how many people are traveling. The calculator uses that to show per-person costs so you can see how the split changes for couples, families, or groups of friends.
2. Add distance and a realistic average speed
Next, add the one-way distance for your route and set an average driving speed. For long interstate drives you might be close to 100–110 km/h or 60–70 mph; for mixed routes with mountains, towns, or heavy traffic, it often makes sense to dial that down. The travel time for driving is simply distance divided by your chosen average speed.
3. Enter car efficiency and fuel price
In US mode, use your car’s mpg and a gas price per gallon. In metric mode, plug in L/100 km and fuel price per liter. The calculator converts those into a total fuel cost for the trip and a per-person share. If you want to sneak in tolls or parking, you can inflate the fuel price a little to approximate those extras without adding more input boxes.
4. Add airfare and airport + transfer overhead
For flying, you enter airfare per person in the same currency as your gas price, ideally including taxes and typical bag fees. Then you set a single airport + transfer overhead number in minutes covering the rideshare or parking, check-in, security, boarding, deplaning, baggage claim, and last mile on the other end. Large hubs at busy times might justify 150–210 minutes; quiet regional airports can often be modeled with 90–150 minutes.
5. Read the recommendation and break-even distances
Hit Compare and the result hero tells you which option comes out ahead, how much time you gain or give up, and how much money you save relative to the alternative. Beneath that you’ll see side-by-side totals for driving and flying, plus approximate time and cost break-even distances. The inline Copy summary button grabs a short text summary you can paste into a trip note or send to whoever you’re planning with.
Because the calculator is input-only with no live data, it stays fast, predictable, and portable. If gas prices spike, a storm rolls in, or you find a sale fare, you can adjust a single number and see how the drive-versus-fly decision shifts, without having to redo all the math yourself.
How the drive vs fly break-even math works
The calculator uses the same structure for both unit systems, with a different cruise speed for planes and a different fuel formula for cars. Let D be the distance (miles or km), v your average driving speed (mph or km/h), and H your airport + transfer overhead in hours.
Driving time is:
Driving time = D ÷ v
Flying time combines a fixed cruise speed with your overhead. In US units the tool uses 500 mph; in metric it uses 800 km/h:
Flying time = H + D ÷ cruiseSpeed
Driving fuel cost depends on unit system. For US units:
Driving cost = (D ÷ mpg) × gasPricePerGallon
For metric units:
Driving cost = (D × L/100 km ÷ 100) × fuelPricePerLiter
Flying cost is airfare per person × number of people, assuming everyone pays roughly the same. The time break-even distance solves for when driving time and flying time match:
Dtime = H ÷ (1/v − 1/cruiseSpeed)
The cost break-even distance solves for when driving fuel cost equals total airfare. In US units that looks like:
Dcost = (airfarePerPerson × people × mpg) ÷ gasPricePerGallon
and in metric units the calculator uses the equivalent form with L/100 km and price per liter. All outputs are rounded, approximate, and meant for planning — always layer them with your own sense of risk tolerance, comfort, and trip flexibility.