Keepwright
How to estimate your yearly mileage.
Ask someone who drives for work how far they travel in a year and you tend to get the same sequence: a shrug, a confident guess, then a quieter, smaller guess. Hardly anyone actually counts. That’s a shame, because for a lot of those people the real figure is worth a few hundred pounds a year in tax relief they never claim — and the only thing in the way is a number they’ve never sat down to work out.
Why the guess always runs low
We’re poor at estimating our own driving, and we’re poor in a predictable direction: low. The long trips are easy to picture — the client two counties over, the airport run. It’s the other twenty journeys that quietly disappear: the supplier you nipped to, the site visit that got rebooked twice, the fortnightly drive so routine you’ve stopped seeing it as a drive at all. Each one is forgettable on its own. Added across a year, they’re often the bigger half of the total.
So the first job isn’t clever. It’s just to count — properly, once.
Three ways to put a number on it
Pick whichever matches how you drive. None of them needs an app; a note on your phone and your odometer will do.
The most accurate is the odometer itself. Write down the reading today and again in two or three weeks, and scale the gap up to a year. If you have a service record or an MOT certificate from twelve months ago, better still — the difference between that reading and today’s is your annual mileage, measured rather than remembered. From the total, take the share that was for work, and that’s your business mileage.
The quickest is a typical week. Add up the business miles you cover in an ordinary week, then multiply by the number of weeks you genuinely work — once holidays and the quiet stretches come off, most people land somewhere near forty-five.
| An ordinary week | × working weeks | ≈ business miles a year |
|---|---|---|
| 60 miles | 45 | 2,700 |
| 120 miles | 45 | 5,400 |
| 250 miles | 45 | 11,250 |
And if your driving is lumpy rather than steady — a handful of routes that repeat, rather than a daily commute — go trip by trip. List each regular journey, its round-trip distance, and how often it happens. A thirty-mile client visit twice a week is sixty miles before anything else joins it. Sum the routes and you have a figure that looks like your actual life, not a round number you’d like to be true.
The part most people get wrong
Now you have a number. Here’s the catch, and it’s the bit worth slowing down for: you can’t claim it.
Not the estimate, anyway. HMRC doesn’t reimburse a guess, and neither will an employer — what they reimburse is a record. The yearly figure you’ve just worked out is for one purpose: deciding whether there’s enough here to bother keeping that record. A few hundred business miles, and perhaps it isn’t worth the bother. Several thousand, and there’s real money on the table — at which point the sensible next step is to start logging the journeys themselves.
What the log needs is unglamorous and specific. For each business journey: the date, where you went — the start and end, and for employees HMRC asks for the start and end postcodes — the reason it counted as business, and the miles. Alongside that, your running total for the year, because the approved rate steps down to a lower band once you pass the first ten thousand business miles. You don’t need odometer readings for the standard flat-rate claim. You need the trips.
An estimate tells you what’s at stake. A record is what you actually claim.
What it comes to
Once you’re working from real miles, the value is plain arithmetic: business mileage times the approved rate — the higher rate for the first ten thousand miles in the tax year, a lower one above. For plenty of people who drive for work, that lands somewhere in the several-hundred-pounds-a-year range, claimed back or reimbursed.
The exact pence per mile is the kind of figure a Budget can move, so it’s worth checking rather than memorising — the current rates are published on gov.uk. If you’d rather not do the sum by hand, drop your estimate into our free mileage calculator and it’ll work the two bands out for you in a second.
Which is the whole point
The distance between a guess and a record is exactly the problem worth solving — and, honestly, it’s why an app like ours exists at all. Keeping that log by hand — every trip, every postcode, tidy enough to survive a question years later — is the part that quietly defeats most people. So they either don’t claim, or they claim a round number they couldn’t stand behind if anyone asked.
The Mileage Tracker has one job here: to capture the real journeys as you drive, in the shape HMRC expects, so the figure you put forward is one you could show an inspector without a second thought. The estimate is where you start. The record is what you keep.
This is general information to help you keep a good record — it isn’t tax advice, and the rules and rates can change. Check current figures on gov.uk, and if your situation is unusual, ask your accountant or HMRC.