Annual miles where lease total cost equals buying the car outright.

350/month lease vs 400/month ownership-equivalent at 15p/mile overage: the lease wins by 50/month. Break-even mileage is the point where penalty miles eat the savings. Below that mileage, leasing is cheaper; above, ownership wins — often with a large swing.

How to use it

Enter monthly lease cost, equivalent monthly ownership cost (depreciation over 3 years plus maintenance and insurance), annual mileage allowance on the lease, and per-mile overage charge.

What the result means

Primary is the break-even annual mileage. Secondary shows monthly savings at the allowance, penalty cost at the break-even point, and 3-year totals for each scenario.

Hidden cost of lease overage

15-25p per overage mile is standard. 5,000 miles over allowance is 750-1,250 extra — often the difference between 'lease saves money' and 'lease costs more'. Underestimating real annual mileage is the most common mistake.

Run it with sensible defaults

Using monthly lease cost of 350, equivalent monthly ownership of 400, annual mileage allowance of 10,000, per-mile overage of 0.15, the calculation works out to 14,000 miles. Nudge the inputs toward your own situation and the output recalculates instantly. The defaults are meant as a starting point, not a recommendation.

The levers in this calculation

The inputs — Monthly Lease Cost, Equivalent Monthly Ownership, Annual Mileage Allowance, and Per-Mile Overage — do not pull with equal force. Not every input has equal weight. Flip one at a time toward extreme values to feel which ones move the needle most for your situation.

How the math works

Annual monthly savings (own minus lease, times 12) is the budget available to pay penalty miles. Dividing by per-mile rate gives extra miles that penalty would cost, above the allowance. Total break-even miles is allowance plus those extra miles. The working is transparent — you can verify every step yourself in the formula section below. No black box, no opaque "proprietary model".

When the result says "wait"

If the payback is longer than you expect to keep the item, the math says no. That's useful information — not everything has to earn its keep financially, but knowing when something doesn't means the decision to buy it anyway is deliberate.

What this doesn't capture

Purchase decisions rarely come down to payback alone. Reliability, time saved, enjoyment, and alternatives outside the calculation all matter. The figure gives you the money side cleanly so you can weigh it against everything else honestly.