The IRS wants a record made close to the time of each trip. For every business trip it expects the date, the destination, the business purpose, and the miles, plus your odometer readings for the year so total and business miles can be shown.
The 2026 standard mileage rates are 72.5 cents a mile for business before July 1 and 76 cents from July 1. Medical miles are 20.5 cents, then 23.5 cents. Charity stays at 14 cents. Milepad picks the right rate from each trip's date, so a log that spans June and July is handled.
Using it for your return
Enter your odometer reading on January 1 and December 31. The report then shows total miles, business miles and the rest, which is what Schedule C asks for if you use the standard rate.
You cannot take the standard rate and actual car costs for the same vehicle in the same year, and the first-year choice matters. Ask your tax preparer which suits you. Milepad calculates the standard-rate figure only.