Calculate Vehicle Cost per Mile from Recorded Expenses

Your vehicle's cost per mile is the total of the expenses you include, divided by the miles driven over the same dates. For example, $3,610 of recorded costs across 12,480 miles works out to about $0.289 per mile. The figure is only meaningful when three things match: the expense categories you count, the start and end dates of the costs, and the odometer readings for those same dates. Change any one of them and the result changes, so a cost-per-mile number should always be reported with its scope and period.

This guide covers looking back at costs you have already recorded, whether you keep them in an Excel or Google Sheets file or on a printable PDF log. It does not cover comparing cars before purchase, mileage reimbursement rates, tax treatment or commercial fleet decisions. Those questions use different rules and are outside this calculation.

The formula and the terms it depends on

Cost per mile = Total costs in scope for the period ÷ Miles driven in the same period

Miles driven  = Odometer reading at end date − Odometer reading at start date

• Expense scope: the categories you decide to count, such as fuel only, running costs, or full ownership costs.
• Period: the exact start and end dates. Every cost and both odometer readings must belong to these dates.
• Odometer: the dashboard counter showing the vehicle's total distance. The odometer is more reliable than adding up trip-meter readings or remembered journeys.
• Recorded cost: an amount you actually paid, backed by a receipt, statement or log entry.
• Estimate: a figure you calculated rather than paid, such as depreciation. Keep estimates labeled so they can be separated from recorded costs.

Decide your expense scope first

The biggest reason two cost-per-mile figures for the same car disagree is that they count different things. Pick one scope before you add anything up, and name it in your spreadsheet or log.

Scope | Typical categories | Answers the question

Fuel or energy only | Fuel, or charging for an electric vehicle | What does it cost to put distance on the car?

Running costs | Fuel or energy, routine maintenance, repairs, tires, tolls, parking | What does using the car cost, apart from fixed bills?

Full ownership | Running costs plus insurance, registration and licensing fees, loan interest, and depreciation (estimated) | What does having and using the car cost in total?

Fixed costs such as insurance and registration are paid whether you drive or not, so they make cost per mile higher in a low-mileage year and lower in a high-mileage year. Running costs tend to rise and fall with distance. That difference is why it helps to calculate both a running-cost figure and a full-ownership figure rather than one blended number.

Match distance and dates to the expenses

• Write down the odometer reading on the start date and on the end date. If you missed the exact day, use the reading closest to it and note the gap.
• Include only costs dated within the period. A repair invoice from the month before the start date belongs to the previous period.
• For fuel, start and end the period on full-tank fill-ups. Fuel bought at the first fill-up of the period largely replaced fuel burned before the period began, so filling to full at both ends keeps fuel spending aligned with the distance it covered.
• Keep a single currency and a single distance unit throughout. If some fuel was logged in liters and some in gallons, convert before totaling.

Handle costs that don't line up with your period

Some bills cover more or less time than your measurement period. An annual insurance premium paid in one installment, for example, should not be counted in full against a three-month period. Prorate it by the share of its coverage that falls inside your dates.

Prorated cost = Bill amount × (Days of coverage inside your period ÷ Total days the bill covers)

Example: $1,140 annual premium, 92 days inside the period
$1,140 × (92 ÷ 365) ≈ $287.34

Depreciation, the loss in a vehicle's value over time, is never a recorded payment. It is an estimate based on a value you assign at the start and end of the period, and different valuation methods give different answers. If you include it, enter it as a separate line marked as an estimate, and report your cost per mile both with and without it. That way, anyone reading the figure can see how much of it rests on a judgment rather than a receipt.

Set up the spreadsheet in Excel or Google Sheets

A simple structure uses two sheets: a Log sheet with one row per expense, and a Summary sheet that pulls totals for the period. The formulas below use standard functions that work in both Excel and Google Sheets. Adjust the sheet names and ranges to match your file.

Log sheet (one row per expense)
  A: Date   B: Odometer   C: Category   D: Amount   E: Type (Actual or Estimate)

Summary sheet
  B1  Start date
  B2  End date
  B3  Start odometer
  B4  End odometer
  B5  Miles driven         =B4-B3
  B6  Total costs          =SUMIFS(Log!D:D, Log!A:A, ">="&B1, Log!A:A, "<="&B2)
  B7  Estimates included   =SUMIFS(Log!D:D, Log!A:A, ">="&B1, Log!A:A, "<="&B2, Log!E:E, "Estimate")
  B8  Recorded costs only  =B6-B7
  B9  Fuel costs           =SUMIFS(Log!D:D, Log!A:A, ">="&B1, Log!A:A, "<="&B2, Log!C:C, "Fuel")
  B10 Cost per mile        =B6/B5
  B11 Recorded per mile    =B8/B5
  B12 Fuel per mile        =B9/B5
  B13 Cost per km          =B10/1.609344

The category names in the formulas must match the Log sheet exactly, including spelling and capitalization habits. One mile is exactly 1.609344 kilometers, so dividing a per-mile cost by 1.609344 gives the per-kilometer cost. If your odometer reads in kilometers, calculate cost per kilometer directly and multiply by 1.609344 to get cost per mile.

Worked example

The numbers below are illustrative only, chosen to show the arithmetic. They are not typical costs for any vehicle or market.

Item | Amount

Start odometer | 42,150 miles

End odometer | 54,630 miles

Miles driven | 12,480

Fuel | $1,560.00

Routine maintenance | $410.00

Repairs | $285.00

Insurance (covering the full period) | $1,140.00

Registration | $120.00

Parking and tolls | $95.00

Total recorded costs | $3,610.00

• Fuel only: $1,560 ÷ 12,480 = $0.125 per mile
• Running costs (fuel, maintenance, repairs, parking and tolls): $2,350 ÷ 12,480 ≈ $0.188 per mile
• All recorded costs: $3,610 ÷ 12,480 ≈ $0.289 per mile
• All recorded costs per kilometer: $0.289 ÷ 1.609344 ≈ $0.180 per km

No depreciation was included here. If you added an estimated depreciation figure, it would sit in its own line marked as an estimate, and you would report both the recorded-only result and the result with the estimate.

Check the result before you rely on it

• Recalculate miles driven by hand from the two odometer readings and compare it with the spreadsheet cell.
• Confirm the total equals the sum of the individual category totals; a mismatch usually means a misspelled category or a row outside the date filter.
• Look for duplicated entries, such as a fuel purchase logged both from a receipt and from a card statement.
• Check units: miles versus kilometers, and US gallons versus imperial gallons or liters. Templates downloaded from other countries may assume different units and currencies.
• Check that every prorated bill uses the correct number of days.
• See whether estimates are labeled and whether the reported figure says if they are included.
• Treat a very short period with caution. A single large repair in a month with little driving can produce a cost per mile that doesn't reflect the vehicle over a longer span.

Spreadsheet or printable PDF log?

Both formats show up when people look for a car cost per mile tracker, and they suit different jobs. A printable PDF log is convenient for writing down fuel stops and odometer readings in the vehicle, but a printed sheet does not calculate anything, so the totals and division must be done by hand or copied into a spreadsheet later. Whether a fillable PDF performs any arithmetic depends on how that particular file was built. A spreadsheet in Excel or Google Sheets handles date filtering, category totals and unit conversion automatically, and makes it easier to rerun the calculation for a different period or scope.

Free and paid templates vary in which expense categories they include, whether they treat depreciation as an estimate, and which units and currency they assume. No specific template has been reviewed for this guide, so before using any of them, compare its categories and formulas with the scope and checks described above.

What the figure can and cannot tell you

A cost-per-mile result describes one vehicle, over one period, under one expense scope. It reflects that period's prices, driving pattern and repair history, so it may not predict future costs, and it is not directly comparable with another vehicle's figure unless both use the same scope, period length and units. It is also not a reimbursement rate or a tax figure; those are set by employers, agencies or tax rules in your jurisdiction and follow their own definitions.