Question: how to calculate standard mileage rate?
Answer: Multiply business miles driven by the IRS rate To find out your business tax deduction amount, multiply your business miles driven by the IRS mileage deduction rate. Let's say you drove 15,000 miles for business in 2020. Multiply 15,000 by the mileage deduction rate of 57.5 cents (15,000 X $0.575).