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How to Write an Estimate

What a usable estimate needs — line items, assumptions, a validity date — and what happens once the client accepts it.

An estimate needs a few basics before it's usable, not just professional-looking: your business name and contact details, the client's name, a date, and an estimate number so either side can refer back to it later without confusion.

Break the price into line items rather than a single number — materials, labor, a trip or call-out fee, whatever actually makes up the job. Use per-unit pricing (an hourly labor rate, a per-item materials cost) where the total naturally depends on quantity, so the number is traceable instead of pulled out of the air.

State your assumptions and what's excluded: "this estimate assumes the wall isn't load-bearing; if it is, the price changes." That single sentence is what protects both sides when the job turns out to be bigger than either of you expected going in.

Give the estimate a validity window — how long you're willing to honor the number. Material and labor costs move, and an estimate with no expiry becomes a stale promise a client can hold you to months later. How long you make it is your call; state one you'll actually keep.

Once the client accepts, convert the estimate into an invoice — same client, same line items, now with a due date and payment terms. The estimate itself shouldn't carry either, since it was never a request for payment.

Ready to write one? Try the free generator — no signup.

Frequently asked questions

How long should an estimate stay valid?
Long enough for the client to decide, short enough that your pricing hasn't drifted. Many solo operators use somewhere between two weeks and a month for service work — the exact number matters less than actually writing one down.
Should I charge for preparing an estimate?
Most solo operators don't for a straightforward job. A detailed estimate that requires a site visit or real engineering time might carry a fee — if so, disclose it up front so it isn't a surprise.
What happens after the client accepts my estimate?
Convert it into an invoice — same client, same line items, now with a due date and payment terms, since the estimate itself was never a bill.
Do I need the client's signature to accept an estimate?
A signature isn't required to have an agreement, but written acceptance — an email reply, a signed copy, a text saying go ahead — protects you if the scope or price is disputed later.