Carpool cost calculator
Trip log in; each family's fair share by miles and children riding, who owes whom and the fewest payments to settle. Free, in your browser.
Load one row per trip: the date, the family that drove, the families whose children rode (Garcia:2 for two kids) and the miles. Pooltally prices each trip at the rate you choose, adds tolls, and splits it among the riders in whole cents. The driver is credited the whole trip, so everyone's balance nets to exactly zero, and the settle-up uses the fewest payments.
Worked example
The sample is a fictional four-family school run on Maple Street in September 2026: 23 trips and 232.4 miles, with the Garcias sending two children. At the IRS business rate the trips are worth $191.12, tolls included. Split per child riding, Lee drove 7 trips and is owed $30.41; Patel owes $13.35. 3 transfers settle everyone: Patel pays Lee $13.35, Okafor pays Lee $9.95, Garcia pays Lee $7.11.
Your trip log stays on your computer
Pooltally reads your file with JavaScript in this browser tab. Names, dates and miles are never uploaded, and trips aren't saved — close the tab and they're gone.
How it works
- Log the trips — date, driver, riders and miles — in the template, or try the sample.
- Pick the rate and the split the group agreed on.
- Share the settle-up: who pays whom, or how many drives each family owes.
FAQ
Is my data uploaded?
No. Your files are read by JavaScript in your browser tab and never sent to us or anyone else. Trips aren't stored, so closing the tab clears them. The rate and split options can be saved in this browser if you ask; the carpool name never is.
What rate per mile should a carpool use?
Whatever the group agrees. Many use the IRS business standard mileage rate because it is public and covers the whole cost of a car: 72.5 cents a mile from January 1, 2026 and 76 cents from July 1, 2026 (70 cents in 2025). Gas money alone is gas price ÷ mpg, often 10–15 cents a mile.
Per child or per family?
Per child charges each family for the seats its children use, so a family with two kids riding pays twice the share of a family with one. Per family splits each trip equally between the households riding. Pooltally shows both.
How does the settle-up work?
Each family's balance is what the trips it drove are worth minus its share of every trip. The largest debtor pays the largest creditor, then the next, until everyone is even — at most one payment fewer than the number of families.
How are the cents handled?
Each trip's cost is rounded to the cent, then split among the riders by rounding every share down and giving the leftover cents to the largest remainders, so the shares always add up exactly to the trip.
Can I deduct carpool miles?
Generally no — driving your own and other people's children to school isn't business travel. Pooltally uses the IRS rate only as a fair price per mile. It is not tax advice.
What's free?
Every family's balance, the settle-up payments, the turns owed, every flag, 3 what-ifs and 12 trips on screen and in print (with a footer). Pro shows every trip and every what-if and adds a statement for every family, the Excel workbook and CSV exports.
Is this tax, legal or insurance advice?
No. Pooltally does the arithmetic on the trips you enter. Keep payments to the shared cost of driving; if you're unsure how your auto policy treats carpools, ask your insurer.