How to Estimate Labour Times Accurately
Written for the UK tradesperson, but the principles apply in most English-speaking countries.
How to Estimate Labour Times Accurately
Labour is where most trade quotes go wrong. Materials can be checked against a price list. Labour depends on your judgement, and a small error multiplies across the whole job. Underestimate by two hours on a £40-an-hour rate and you've given away £80. Do that on every job for a year and you've given away a large part of your profit.
Labour is only one part of a price, but it is usually the biggest and the hardest to get right. If you want the full picture of labour, materials, overheads and profit, read our guide on how to price a job properly. This post deals with labour time in detail.
Accurate labour estimating is not a talent. It is a method, and anyone can learn it.
Why labour estimates go wrong
Most bad labour estimates have one of four causes:
Guessing the whole job in one go. "A bathroom takes about a week" is a guess. It isn't an estimate.
Confusing labour hours with elapsed time. A job that takes three days on site may only be 16 labour hours, because of drying times, deliveries and waiting on other trades. It could also be 48 hours if two of you are working.
Forgetting the hidden tasks. Travel, setting up, protecting floors, clearing away, testing, paperwork and the handover all take time. If you don't count them, you don't get paid for them.
Never checking estimates against what actually happened. If you never compare your estimate with the real time, you keep repeating the same mistakes.
The method below fixes all four.
Step 1: Break the job into tasks
Never estimate a job as a single figure. Break it down into individual tasks you can picture yourself doing, and estimate each one separately.
A bathroom refurbishment is not one job. It is a strip-out, first-fix plumbing, boarding, tiling, fitting the suite, second fix, sealing, cleaning and handover. Each of those can be broken down further. The more you break a job down, the more accurate your estimate becomes, because small errors on individual tasks tend to cancel each other out. A single big guess gives you no such protection.
A task breakdown also shows you what you've missed. It is hard to forget "remove and dispose of old suite" when it has its own line on the page.
Step 2: Estimate in labour hours, not days
Estimate every task in labour hours, meaning the time one person spends actually working on it. Work out elapsed time (how many days you'll be on site) separately, afterwards, once you know how many people are on the job and where the waiting time falls.
The two figures do different jobs. Labour hours set your price. Elapsed time sets your programme and tells the customer when you'll be finished. If you mix them up, you'll either overcharge and lose the job or undercharge and lose money.
Step 3: Use three figures for every task
Most tasks don't take the same time every time. Give each task three figures:
Easy: good access, modern construction, empty property, nothing unexpected.
Average: the typical job.
Difficult: poor access, old or unusual construction, occupied property, likely surprises.
Then decide at the survey which band this particular job falls into, and be clear with yourself about why.
Take a consumer unit replacement as an example. A reasonable spread might be Easy 6–7 hours, Average 8–10 hours, Difficult 12–16 hours. A straightforward swap in a modern house sits in the Average band at around 8 hours. The same job in an older property with mixed wiring and no labels on anything moves into the Difficult band, and your price has to move with it.
The three-band approach makes you ask what could make this job harder, which is exactly the question a guess skips.
Step 4: Add the time you normally forget
Once your task list is complete, go through it again and add:
Travel to and from site, and trips to the merchant
Setting up, dust sheets and floor protection
Clearing up each day and at the end
Waste removal
Testing, commissioning and certification
Talking to the customer and the handover
These are real labour hours. If they aren't in the estimate, you're working them for free. Travel also costs you money on top of the time: fuel, insurance, finance and wear on the van. The TradeProfit app converts your van costs into a real cost per mile so travel is priced properly on every job.
Step 5: Adjust for the conditions on this job
Now look at the things that slow you down on this specific site:
Access (stairs, loft space, parking, distance from the van)
Working in an occupied home
Height and working platforms
Age and condition of the property
Weather, for outdoor work
Working around other trades
Some of these belong in your choice of band (Step 3). Genuine unknowns, such as what's behind a wall you haven't opened, belong in a separate contingency allowance, not buried in your labour hours. Keep the two separate so you always know which part of your price covers work and which covers risk.
Step 6: Cross-check your figures
Before you commit to a figure, check it against something independent. Useful cross-checks include:
Your own records from similar past jobs (the best source by far)
Published productivity rates for your trade
An AI tool such as ChatGPT or Claude, asked for an Easy/Average/Difficult range for the task
Use AI as a second opinion, not an authority. Ask it where its figures come from and check the source. AI can produce a sensible-looking range based on a consumer blog written by someone who has never done the job. If the AI figure and your own figure agree, that's reassuring. If they don't, find out why before you send the quote.
Step 7: Record what actually happened
This is the step that turns a reasonable estimator into an accurate one, and it is the step most tradespeople skip.
After every job, compare the hours you estimated with the hours the job actually took, and note the reason for any difference. Within six months you'll have a record built from your own work, your own speed and your own type of job. No published price book can match that, because published figures are averages from other people's jobs.
Different tradespeople take different times for the same task. The only figures that are accurate for you are your own.
This is exactly what the TradeProfit app's forecast vs actual feature does. You enter your estimated hours when you create the job and log the actual hours when you close it. The app shows the two side by side, along with your real profit, so you can see which types of job you estimate well and which ones you consistently underestimate.
Step 8: Convert hours into a price
Only now do you turn hours into money, by multiplying your labour hours by your hourly rate. That rate must cover your overheads and profit, not just your wages. An accurate labour estimate multiplied by the wrong rate still gives you the wrong price. Our guide on calculating labour, overheads and profit before you quote explains how to get that rate right.
The short version
Break the job into tasks. Estimate each task in labour hours. Give each task an Easy, Average and Difficult figure, and pick the band at the survey. Add the hidden time. Keep unknowns in contingency, not in your hours. Cross-check. Record the actual time on every job, and use those records next time.
Do this consistently and your labour estimates stop being guesses and become figures you can defend to a customer and to yourself.
Find out whether your estimates are actually right
Most tradespeople never find out whether their labour estimates were accurate. They finish the job, get paid and hope they made money.
TradeProfit shows you. Set your rates once, enter your estimated hours when you create a job, and log the actual hours when you finish. You'll see your real profit and your estimate against reality on every job, including van, travel, materials and labourer costs. It's free for your first 10 jobs, and no credit card is needed.
Know your real profit on every job.
Want to go further? The Complete Guide to Estimating for Tradespeople covers this method in full, with worked estimates across 15 trades. It comes with a free estimating toolkit including AI cross-check prompts and a template for building your own labour-time database.