How it works
Start with the maintenance schedule for the exact vehicle and the relevant driving conditions. Enter the cost of one recurring service and its time and distance intervals. The calculator uses the earlier interval by taking the larger annual service rate. If your schedule contains several different service types, use this row for the common recurring service and budget other work separately.
The tire allowance spreads the price of a future installed set over an assumed driving distance. It does not inspect tire condition or determine a replacement date. Known work due now is counted once, while the other annual reserve covers work not already included in service or tires. The main monthly figure is recurring savings; the second monthly average also spreads immediate work across the planning period.
The formula behind the estimate
Every result starts with a defined model and visible assumptions.
Annual routine service reserve = service price × max(annual distance ÷ service distance interval, 12 ÷ service month interval) Annual tire reserve = installed tire-set cost × annual distance ÷ tire distance allowance Annual recurring reserve = service reserve + tire reserve + other annual reserve Period budget = recurring reserve × years + known work due now Monthly recurring reserve = annual recurring reserve ÷ 12
A worked example
With 12,000 miles per year, a $150 service every 6,000 miles or six months gives a $300 annual service reserve. A $600 tire set spread over 40,000 miles adds $180 per year. Adding a chosen $300 other annual reserve gives $780 per year, or $65 per month. Over five years the recurring budget is $3,900; any known work due now is added once. All amounts and intervals are illustrative.
A reserve is different from a service calendar
A fractional annual service rate is useful for smoothing a savings target. For example, 1.5 services per year means saving for three services over two years. Actual appointments depend on the last service date, odometer, driving conditions and manufacturer instructions. This calculator does not collect that history and therefore does not predict an appointment date.
Tire age, tread, damage, load and operating conditions can require replacement before the entered distance allowance. Budgeting does not replace inspecting the vehicle or following its manufacturer instructions.
Keep maintenance separate from a repair quote
An annual reserve is money set aside against uncertain future work. A written repair quote is a specific proposed job. Put a known job in work due now, and avoid also adding the same amount to the recurring reserve. A larger reserve can be a useful stress test, but it is not a vehicle reliability forecast.
This plan holds prices and driving distance constant. Refresh quotes and intervals when the vehicle or usage changes, and carry the maintenance budget into a full ownership comparison only once.
Questions worth asking
How much should I save each month for maintenance?
Use the monthly reserve from your own service schedule, quotes, tire allowance and other annual work. The example is not a universal recommended amount.
Does time or mileage determine service frequency?
The model uses whichever interval is reached sooner, expressed as an annual reserve rate. Follow the exact manufacturer schedule for actual servicing.
Why is the service rate fractional?
It is an amortized savings rate rather than a count of services due in the next calendar year.
Does the tire interval tell me when tires are safe?
No. It is only a savings assumption. Tire age, condition, wear and manufacturer instructions determine replacement needs.
Can I use kilometers and another currency?
Yes. Switching distance units converts the distance inputs together. Eight currency choices change labels; monetary amounts are not exchanged automatically.
This is general information, not personalized financial advice. Read the limitations.
