What the Mileage Reimbursement Calculator does
This calculator turns a trip log into a mileage claim. It handles the part a spreadsheet usually gets wrong: a tiered scheme where the rate drops after a cumulative threshold, and the single journey that straddles that threshold and has to be split across two rates. Each trip shows the split, the cumulative distance before and after, and any passenger supplement.
No rates are built in, and none are guessed. Mileage allowances differ by country, by employer, by vehicle and by tax year, and in many systems anything above an approved rate is taxable pay. You enter the scheme; the page does the arithmetic and says plainly that your policy and your tax authority decide what is actually payable.
How to use it
- Enter the rate for the first tier, the cumulative threshold and the rate above it. Leave the threshold blank for a single flat rate.
- Enter the distance already claimed in the current year, so the tier position starts in the right place. This is the field people forget, and it is usually worth the most money.
- Add a passenger rate if your scheme pays one - it is applied per passenger per unit of distance and is not tiered.
- Paste the trip log, one line per journey:
date, purpose, distance, passengers. - Read the claim, check any split trips in the section below the table, and download the claim sheet.
Reading the results
The cumulative column is what drives the rate. A trip is paid at whichever tier the running total is in when that distance is travelled, which is why the order of the trips matters.
A trip shown in amber crossed a threshold and was paid partly at each rate; the split is written out underneath the table.
The average rate per unit is the whole claim divided by the whole distance. It is the number to quote when someone asks why the claim is not simply distance times the headline rate.
If some distance falls beyond your highest threshold with no further tier, it is paid at nothing and flagged. Add an open-ended final tier if the scheme keeps paying.
Worked example: a two-tier scheme crossed mid-journey
A scheme pays 0.45 per mile for the first 10,000 miles of the year and 0.25 after that. The claimant has already claimed 9,800 miles, and submits four September trips: 128, 212, 86 and 174 miles - 600 in total.
The first trip runs from 9,800 to 9,928 miles, entirely in the first tier: 128 x 0.45 = 57.60.
The second runs from 9,928 to 10,140 and crosses the threshold. Seventy-two miles are paid at 0.45 (32.40) and 140 at 0.25 (35.00), so the trip pays 67.40 rather than the 95.40 a flat 0.45 would give.
The third and fourth are wholly in the second tier: 86 x 0.25 = 21.50 and 174 x 0.25 = 43.50.
The claim totals 190.00, an average of 0.3167 per mile. Treating all 600 miles as first-tier would have produced 270.00 - eighty pounds of overclaim from one forgotten threshold.
Formulas and scoring rules
- Tiered distance payment
for each tier: min(remaining, tier ceiling - cumulative) x tier rateApplied in order, so one journey can be split across two rates.- Passenger supplement
passengers x passenger rate x distanceNot tiered: the supplement is the same whatever the cumulative distance.- Trip total
trip = distance payment + passenger supplement- Average rate
average = claim total / total distanceLower than the headline rate whenever a threshold has been crossed.- Against an approved scheme
difference = amount paid - approved amountA positive difference is the excess many tax systems treat as pay; a negative one is what some allow as relief.
Why the threshold is cumulative, and what that means for order
Tiered mileage schemes count distance across the whole tax or policy year, not per claim and not per journey. A claim submitted in September is priced by where the year's running total already stood, which is why the "already claimed" field matters more than any other input on this page.
It also means the order of trips inside a claim can change individual trip values, though never the total. The page shows the cumulative figure before and after each trip so the claim can be reconciled against a previous one.
What a mileage record has to contain
Most employers and most tax authorities expect each business journey to carry a date, a purpose, the start and end points and the distance. The purpose is the one people leave blank, and it is the one that decides whether a journey is business travel at all - ordinary commuting usually is not.
The page flags trips with no date and trips with no purpose. They are only warnings, because your scheme may not need them; they are there because a bare column of distances is not a record.
Limitations: what the result does not prove
- It contains no published rates and does not know which scheme applies to you. Rates change annually and differ by country, vehicle type and engine size.
- It does not decide whether a journey is business travel. Commuting, mixed journeys and travel to a temporary workplace are treated very differently by different tax systems.
- It does not calculate tax. Where an employer pays more than an approved rate, the excess is often taxable; where it pays less, relief may be available. The comparison box shows the difference, not the tax effect.
- Distances are the ones you enter. No mapping, routing or geolocation is used - nothing about your journeys leaves the browser.
Privacy: where your data goes
Everything you paste, type or drop is processed in this browser tab. It is not uploaded, logged, stored or sent to analytics. Session recording and tag-manager scripts are switched off on this page.
Standards and sources
Frequently asked questions
How do I calculate a mileage claim with a tiered rate?
Work out where the year's cumulative distance stands before each trip, pay the distance up to the threshold at the higher rate and the rest at the lower one. This calculator does that automatically and writes out the split for any journey that crosses the threshold.
What happens to a single journey that crosses the mileage threshold?
It is split. The miles travelled below the threshold are paid at the first rate and the rest at the second, because the threshold applies to cumulative distance rather than to whole journeys. The page shows both parts so the figure can be checked.
Do passenger payments also drop after the threshold?
In the schemes that offer them, no - the passenger supplement is normally a flat amount per passenger per mile or kilometre with no threshold. This calculator treats it that way and reports it separately from the distance payment.
Why is my average rate lower than the headline rate?
Because part of the distance was paid at the lower tier. The average rate is the claim divided by the distance, and it is the quickest way to show someone that a claim is not simply distance times the advertised figure.
Does commuting count as business mileage?
Usually not. Most tax systems treat travel between home and a permanent workplace as ordinary commuting, which is not reimbursable tax-free, while travel to a temporary workplace or between sites often is. The rules are specific to your country, so check them rather than assuming.
What if my employer pays less than the approved rate?
Enter the approved amount in the comparison box and the page shows the shortfall. Several tax systems allow relief on that difference, but whether and how you claim it depends on where you are, so treat the figure as the starting point for that question.
Is my trip log sent anywhere?
No. The log stays in the browser tab - there is no upload, no map lookup and no storage. Download the claim sheet if you need to keep it.
Last reviewed by the A2Z.Tools team against the sources listed above.
