Most garage owners know what they took last month. Far fewer know whether it was a good month.
Five garage KPIs, or key performance indicators, answer that. You can work all of them out from your garage system and your accounts in about ten minutes. Each points at a different problem: what customers spend, what you really earn for an hour of labour, whether your technicians’ time turns into sales, what you keep on parts, and what you must take just to stand still.
Two ground rules. Use figures excluding VAT throughout. And treat every benchmark below as a rule of thumb: most published ones come from software vendors or one person’s experience rather than a survey, and one vendor guide admits it found no primary data behind the averages other sites repeat. Your best benchmark is your own figure from last year.
1. Average invoice value
What it is. Average invoice value is how much a customer spends each time they visit.
Work it out. Sales excluding VAT, divided by the number of invoices. Our invented example garage took £28,000 across 112 invoices, which is £250.
What good looks like. Garage Industry Trends, a data service run by Garage Hive using more than 175 independent workshops, put the UK average at £300 in 2024, up from £285. Don’t chase that figure. A garage doing mostly MOTs will sit below one doing mostly repairs, and in the same data diesel jobs averaged £342.61 against £227.84 for electric. Compare yourself with your own last twelve months, split by type of job.
If it’s weak. Look at what leaves the garage unquoted: advisories that never become booked work, the second job nobody mentioned, parts and consumables that never reach the invoice. Keep it honest. An average built on trust holds; one built on pressure shows up later as customers who don’t come back.
2. Effective labour rate (posted vs collected)
What it is. Your effective labour rate is the hourly rate you actually collect, as opposed to the posted rate on your board.
Work it out. Labour income divided by hours sold, with parts left out. The example garage earned £14,000 of labour on 224 sold hours: £62.50 an hour. Its posted rate is £75, so it collects 83% of it and is £12.50 an hour short. Over 224 hours that is £2,800 a month, or £33,600 a year.
Some systems show a “labour rate” column that is already the rate you achieved, not the one you set. Check which one you are looking at.
What good looks like. One workshop-software vendor says a healthy workshop collects 80–90% of its posted rate and calls anything below 80% a leak. That is a rule of thumb, not a UK survey result. And note that this garage sits inside that range and still loses £33,600 a year.
If it’s weak. The gap is usually the same few things: discounts at the counter, free checks and goodwill hours, fixed-price menu jobs still priced from an old rate, quotes that overrun, and different rates quoted by different people. Pull last month’s ten most-discounted jobs and sort them by reason. The pattern is usually obvious. Then fix it with a rule (who can discount, and by how much), not a reminder.
3. Technician efficiency and how to calculate it
What it is. Technician efficiency is the share of the hours you pay your technicians for that you actually sell.
Work it out. Hours sold divided by hours paid. Two technicians paid for 160 hours each is 320 hours. Sell 224 of them and efficiency is 70%.
Watch the jargon. Guides use efficiency, utilisation and productivity for different ratios; one UK vendor measures time on jobs against hours attended and calls 85–95% normal. Pick one definition, write it down, and never compare across definitions.
What good looks like. For hours sold against hours paid, the usual rule of thumb for a well-run independent is 75–85%, and garages measuring for the first time commonly find 65–78%. In 2018 Andy Savva, a former garage owner writing in Professional Motor Mechanic, reported an average of about 60% across the UK garages he had visited and called 80% a realistic target.
If it’s weak. The unsold hours (96 a month in the example) hide in two places: time with no job to do (waiting for parts, waiting for approval, nothing booked) and time on jobs that never gets charged (slow jobs, comebacks, unbilled diagnosis). Find out which is bigger before you act. Book further ahead and get approval faster for the first; charge for diagnosis and compare quoted against actual job times for the second. Each 5 points on two technicians is 16 more hours a month, about £1,000 at £62.50.
[FIRST-HAND LINE: one anonymised sentence on what you found the first time you measured this in a real garage.]
4. Gross margin and parts margin
What it is. Gross margin is the share of each pound of sales left after you pay for what you bought to deliver it, which in most garages means parts.
Work it out. Sales minus cost of sales, divided by sales. In the example, £28,000 of sales less £9,100 of parts leaves £18,900: a gross margin of 67.5%. Work out parts on their own as well. £14,000 of parts that cost £9,100 is a parts margin of 35%.
Ask your accountant where technician wages sit. Here they count as an overhead, which is what the break-even sum below needs. If yours sit in cost of sales, your gross margin will look far lower and no published range will match it.
And markup is not margin. Buy a part for £60, add 50% and sell it for £90. You made £30 on £90: a margin of 33%, not 50%.
What good looks like. There is no reliable published UK benchmark. The nearest thing is a 2015 thread on the AccountingWeb forum where members quoted 60–72% for general and mobile garages and 83% for a specialist with a high hourly rate. Nobody said how they treated wages. For parts, Andy Savva recommended an average margin of 40%, and his own garage worked to a floor of 35%.
If it’s weak. Gross margin moves for three reasons: your mix of parts to labour, parts prices that haven’t followed supplier increases, and parts used but never invoiced. Check your pricing against today’s cost prices, then compare parts bought with parts invoiced.
5. Garage break-even point
What it is. Your break-even point is the sales you need each month just to cover your costs.
Work it out. Monthly overheads divided by gross margin. Overheads here means every cost that isn’t in cost of sales: all wages including yours, rent, rates, insurance, software and finance. In the example, £16,000 of overheads at a 67.5% gross margin gives £23,704 of sales. That is about £1,185 a day over 20 working days, or 95 invoices at £250.
The garage took £28,000, so its cushion is £4,296, about 15% of sales. That cushion is what pays for a bad month.
What good looks like. There is no benchmark, because break-even belongs to your garage. Watch the size of the cushion and which way it is moving.
If it’s weak. Only two levers exist: lower the overheads, or earn more gross profit from each job, which is what numbers 2, 3 and 4 are for. Overheads cost more than they look. At a 67.5% margin, each extra £1,000 a month needs about £1,480 more sales to pay for it. Before you sign for another hire, lease or subscription, work out the sales it needs.
How the five garage KPIs fit together
The five numbers are connected. The example garage posts £75 an hour, collects £62.50 on the hours it sells, and sells 70% of the hours it pays for. Multiply those together and each paid hour brings in £43.75, which is 58% of the rate on the board. Find your own version of that gap and you know where to look first.
Your ten-minute monthly KPI check
Do it on the same day each month, with the same definitions, in one place you can look back at.
| Number | Inputs | Where to find them |
|---|---|---|
| Average invoice | Sales excluding VAT; number of invoices | Sales report from your garage system |
| Effective labour rate | Labour income; hours sold | Labour sales and hours-sold reports |
| Technician efficiency | Hours sold; hours paid | Hours sold from your system; hours paid from the rota or payroll |
| Gross margin | Sales; cost of parts and other direct costs | Profit and loss account |
| Break-even | Overheads; gross margin | Profit and loss account |
The first month takes an afternoon. After that it is ten minutes, and your trend is worth more than any benchmark here.
Knowing your numbers also tells you what it is worth spending to find more customers. Next on Garage Gurus is The Real Numbers: each month we take one real garage’s figures, anonymised and scaled, and show what they mean. [NEWSLETTER SIGN-UP LINK]
Garage KPI questions, answered
What are the most important garage KPIs?
Five cover most of what an owner needs: average invoice value, effective labour rate, technician efficiency, gross margin and break-even point. Check them monthly, excluding VAT, using the same definitions each time.
How do you calculate technician efficiency?
Divide the hours you sold by the hours you paid your technicians for, then multiply by 100 for a percentage. Two technicians paid for 320 hours who sell 224 are at 70%. Check how your software defines it, because some guides measure against hours clocked onto jobs instead.
What is a good technician efficiency for a garage?
The usual rule of thumb for a well-run independent is 75–85% of paid hours sold, and garages measuring for the first time commonly find 65–78%. These come from software vendors, not surveys, so watch your own trend too.
What is effective labour rate?
It is the hourly rate you actually collect: labour income divided by hours sold. A garage that posts £75 an hour but earns £14,000 on 224 sold hours collects only £62.50, once discounts, goodwill work and underpriced fixed-price jobs are counted.
How do you work out a garage’s break-even point?
Divide your monthly overheads, including all wages and your own pay, by your gross margin. With £16,000 of overheads and a 67.5% gross margin, break-even sales are about £23,700 a month.
What is a good gross margin for a garage?
There is no reliable published UK benchmark, and it depends on whether technician wages sit in cost of sales. Forum members have quoted 60–72% for general garages. For parts, one former garage owner recommended an average margin of 40%.
What is the average invoice value for a UK garage?
Garage Industry Trends, which draws on data from more than 175 independent workshops, put it at £300 in 2024, up from £285. Your own figure depends on your mix of MOTs, servicing and repairs.
