How car vs bike is worked out
Driving and cycling are priced on different things, so the fair comparison is the net cost over the same 25 years and the same commute. The miles per year are the one-way miles times 2, for the trip there and the trip back, times the workdays per year. The car side buys two cars over 25 years, one at the start and one at year 12, and pays the running cost on every mile. The bike side buys five bikes over 25 years, one every 5 years, and pays its own running cost on every mile. The net cost on each side is the gross cost minus the resale value at the end, because the car and the bike are both sold. The net winner is the smaller net cost, and the gap between the two nets is how much the winner wins by.
At the defaults — 12 miles one-way, 220 workdays a year, car $25,000 at $0.65 a mile, resale $8,000, bike $1,200 at $0.10 a mile, resale $200 — the commute is 12 × 2 × 220 = 5,280 miles a year, the car running is 5,280 × $0.65 = $3,432.00 a year, or $85,800.00 over 25 years, and the car gross is 2 × $25,000.00 + $85,800.00 = $135,800.00, so the car net is $135,800.00 − $8,000.00 = $127,800.00. The bike running is 5,280 × $0.10 = $528.00 a year, or $13,200.00 over 25 years, and the bike gross is 5 × $1,200.00 + $13,200.00 = $19,200.00, so the bike net is $19,200.00 − $200.00 = $19,000.00 — and the bike wins net by $127,800.00 − $19,000.00 = $108,800.00.
| Case | Car net | Bike net | Net winner |
|---|
| 12 mi, car $0.65/mi (default) | $127,800.00 | $19,000.00 | Bike by $108,800.00 |
| 6 mi one-way | $84,900.00 | $12,400.00 | Bike by $72,500.00 |
| Car $0.85/mi | $154,200.00 | $19,000.00 | Bike by $135,200.00 |
| Bike $2,500 | $127,800.00 | $25,500.00 | Bike by $102,300.00 |
| Car resale $0 | $135,800.00 | $19,000.00 | Bike by $116,800.00 |
| 20 mi one-way | $185,000.00 | $27,800.00 | Bike by $157,200.00 |
The worked example, line by line
Setup: 12 miles one-way, 220 workdays a year, car $25,000 at $0.65 a mile, resale $8,000, bike $1,200 at $0.10 a mile, resale $200.
Line 1 — the miles. 12 × 2 × 220 = 5,280 miles a year, or 132,000 miles over 25 years.
Line 2 — the car running. 5,280 × $0.65 = $3,432.00 a year, and $3,432.00 × 25 = $85,800.00 over 25 years.
Line 3 — the car net. 2 × $25,000.00 + $85,800.00 = $135,800.00 gross, and $135,800.00 − $8,000.00 = $127,800.00 net, or $5,112.00 a year.
Line 4 — the bike running. 5,280 × $0.10 = $528.00 a year, and $528.00 × 25 = $13,200.00 over 25 years.
Line 5 — the bike net. 5 × $1,200.00 + $13,200.00 = $19,200.00 gross, and $19,200.00 − $200.00 = $19,000.00 net, or $760.00 a year.
Line 6 — the net winner. $127,800.00 − $19,000.00 = $108,800.00 to the bike. Upfront the bike wins by $25,000.00 − $1,200.00 = $23,800.00, and the break-even bike price is ($127,800.00 − $13,200.00 + $200.00) ÷ 5 = $22,960.00.
Every branch, checked
6 miles one-way: the commute falls to 6 × 2 × 220 = 2,640 miles a year, so the car running is $1,716.00 a year and the car net is $84,900.00, while the bike running is $264.00 a year and the bike net is $12,400.00 — so the bike wins net by $72,500.00. A shorter commute shrinks the gap, because the car’s running cost is what the bike saves on, but the bike still wins by a wide margin.
Car $0.85 a mile: the car running rises to 5,280 × $0.85 = $4,488.00 a year, or $112,200.00 over 25 years, so the car net is $154,200.00 and the bike wins net by $135,200.00. A dearer car — a thirsty engine, dear insurance, or dear repairs — widens the gap, because every extra cent a mile is $132 a year on this commute.
Bike $2,500: five bikes at $2,500.00 cost $12,500.00, so the bike gross is $25,700.00 and the bike net is $25,500.00, and the bike wins net by $102,300.00. Even a dear bike — an e-bike, or a bike with good lights and panniers — is far cheaper than the car over 25 years.
Car resale $0: with no resale value at the end, the car net is the whole $135,800.00 gross, so the bike wins net by $116,800.00. A car that is worth nothing at the end is the car’s worst case, and it still does not change the answer.
20 miles one-way: the commute rises to 20 × 2 × 220 = 8,800 miles a year, so the car running is $5,720.00 a year and the car net is $185,000.00, while the bike net is $27,800.00 — so the bike wins net by $157,200.00. A longer commute widens the gap, because the car’s running cost grows with every mile while the bike’s stays small.
Reverse — the break-evens: the bike ties the car if it costs $22,960.00 — a bike dearer than most cars, let alone most bikes. And there is no break-even car running cost: even a car that ran free would cost 2 × $25,000.00 − $8,000.00 = $42,000.00 net, against the bike’s $19,000.00. The car cannot win on money at these prices; it wins on comfort, cargo and dry clothes.
What the defaults assume
The model assumes the same commute every workday for 25 years, two cars over that time and five bikes, and that the running cost per mile covers everything: fuel, insurance, servicing, tyres and repairs for the car, and tyres, chains, brake pads and servicing for the bike. It assumes the car is replaced once at year 12 and the bike every 5 years, and that both are sold at the end for the resale value entered. It leaves out parking, tolls and fines, the cost of the driver’s time, and the health value of cycling — and it leaves out the cost of a second car for the household. Rounding convention: money is rounded to cents, miles to 2 decimals, and all figures are computed from unrounded values, rounded only for display.
Output · formula · meaning
| Output | Formula | What it means |
|---|
| Miles per year | one-way miles × 2 × workdays/yr | 5,280.00 miles. |
| Car running/yr | miles/yr × car $/mile | $3,432.00. |
| Car gross | 2 × car price + car running × 25 | $135,800.00. |
| Car net | car gross − car resale | $127,800.00. |
| Bike running/yr | miles/yr × bike $/mile | $528.00. |
| Bike gross | 5 × bike price + bike running × 25 | $19,200.00. |
| Bike net | bike gross − bike resale | $19,000.00. |
| Net winner | car net − bike net | Bike wins by $108,800.00. |
| Car net/yr | car net ÷ 25 | $5,112.00/yr. |
| Bike net/yr | bike net ÷ 25 | $760.00/yr. |
| Upfront winner | car price − bike price | Bike wins by $23,800.00. |
| 6 mi one-way | same model, 6 miles | Car net $84,900.00, bike net $12,400.00, Bike wins by $72,500.00. |
| Car $0.85/mi | same model, car $0.85 | Car net $154,200.00, Bike wins by $135,200.00. |
| Bike $2,500 | same model, bike $2,500 | Bike net $25,500.00, Bike wins by $102,300.00. |
| Car resale $0 | same model, resale $0 | Car net $135,800.00, Bike wins by $116,800.00. |
| 20 mi one-way | same model, 20 miles | Car net , bike net , . |
| Reverse: break-even bike price | (car net − bike running × 25 + bike resale) ÷ 5 | $22,960.00. |
| Reverse: car that ran free | 2 × car price − car resale | $42,000.00 net, still more than the bike’s $19,000.00. |
Who uses this
- The commuter weighing a bike for the first time: they learn the bike wins by $108,800.00 over 25 years — $127,800.00 to drive against $19,000.00 to ride — so they know the bike is not a small saving, it is a different scale of cost, and they know the car still wins on comfort and cargo.
- The worker with a short 6-mile commute: they learn the bike wins by $72,500.00 even on a short commute — so they know the bike is worth trying even when the drive is short, because the car’s running cost is what the bike saves on.
- The driver whose car costs $0.85 a mile to run: they learn the car net is $154,200.00 and the bike wins by $135,200.00 — so they know a thirsty car or dear insurance makes the bike case stronger, not weaker, and they check the running cost per mile before they decide.
- The commuter eyeing a $2,500 e-bike: they learn a $2,500 bike leaves a bike net of $25,500.00 — still $102,300.00 ahead of the car — so they know the dear bike does not change the answer, it just makes the ride easier.
Accuracy & limitations
The math is exact for the numbers you enter: the miles per year are the one-way miles times 2 times the workdays, the car gross is two cars plus the running cost over 25 years, the bike gross is five bikes plus its running cost, and each net is the gross minus the resale value. What the model cannot do is price your time: check what an hour of your time is worth, and add the time the bike takes against the time the car takes, because a slower bike can cost more in time than it saves in money. It leaves out parking, tolls and fines, the health value of cycling, and the cost of a second car for the household. It assumes the same commute every workday for 25 years, which is a long time to hold one job and one address. For the same commute by car alone, see bike vs car commuting; for sharing the drive, see carpool vs driving alone.
Cite this calculatorBright Side Kit. “Car vs Bike Commuting Calculator: 25-Year Cost 2026.” brightoolbox.com, 2026. Method: miles/yr = one-way miles × 2 × workdays/yr; car gross = 2 × car price + miles/yr × car $/mile × 25; car net = car gross − car resale; bike gross = 5 × bike price + miles/yr × bike $/mile × 25; bike net = bike gross − bike resale; net winner = car net − bike net; break-even bike price = (car net − bike running × 25 + bike resale) ÷ 5. Defaults: 12 mi one-way, 220 workdays/yr → 5,280 mi/yr; car $25,000, $0.65/mi, resale $8,000 → car running $3,432.00/yr, gross $135,800.00, net $127,800.00, $5,112.00/yr; bike $1,200, $0.10/mi, resale $200 → bike running $528.00/yr, gross $19,200.00, net $19,000.00, $760.00/yr; bike wins net by $108,800.00; 6 mi → car net $84,900.00, bike net $12,400.00, bike wins by $72,500.00; car $0.85/mi → car net $154,200.00, bike wins by $135,200.00; bike $2,500 → bike net $25,500.00, bike wins by $102,300.00; car resale $0 → car net $135,800.00, bike wins by $116,800.00; 20 mi → car net $185,000.00, bike net $27,800.00, bike wins by $157,200.00; break-even bike price $22,960.00; a car that ran free would cost $42,000.00 net vs the bike’s $19,000.00.Bright Side Kit. "Car vs Bike Commuting Calculator: 25-Year Cost 2026." https://brightoolbox.com/car-vs-bike-calculator/ Accessed October 25, 2026.
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