How to estimate a project without underquoting

To estimate a project without underquoting, split it into tasks small enough to price, estimate the uncertain ones three ways, add a buffer for what you cannot see, and quote a range before a fixed price. Then write the scope down. Underquoting starts when a vague request turns into one confident number too early.

Projects miss their estimates, so plan for it

Assume your first instinct is optimistic, because the research on real projects says most are. Wellingtone's State of Project Management report says only 36% of organizations always or mostly complete projects on time (Wellingtone). Those are teams with project managers, tools and formal processes. A solo operator with a two-line brief is not better placed than they are.

Software projects show the same drift in numbers. A study of 1,471 IT projects by Flyvbjerg and Budzier found an average cost overrun of 27%, and one project in six overran by about 200% (arXiv, also on SSRN). That sample is IT, not creative work, but the lesson carries: the average overrun is bad, and the tail is worse.

Scope is a large part of it. The Project Management Institute's 2018 Pulse of the Profession found that 52% of projects had scope creep or uncontrolled changes, up from 43% five years earlier (PMI). That figure is older than the rest here, and PMI has not published a comparable one since, so read it as history, not a current rate.

Underquoting hits solo workers hardest because you carry the overrun yourself. There is no client budget or team to absorb it. So the aim is not a lucky guess. It is a number you can defend, tied to work you have actually thought through.

Step 1: Break the work into tasks you can price

You cannot price a project. You can price a task. Turn "redesign the website" into pieces small enough to put a number on without flinching: discovery call and notes, sitemap, wireframes for five templates, visual design for those templates, one revision round, developer handoff files and a final walkthrough.

Two rules keep this honest. If a task is too big to estimate in one sitting, it is not a task yet, so split it. "Build the dashboard" is a project. "Build the filters, the table and the export" is three tasks.

Second, list the work that is not the deliverable. Kickoff, status updates, review cycles, exports, admin and the back-and-forth about fonts. This is where solo estimates leak. You bill for the deliverable and absorb the coordination, then notice a $3,000 project paid like $18 an hour once you divide by the hours it really took.

Step 2: Estimate uncertain tasks three ways

For work you have done many times, one number is fine. For anything with unknowns, give each task three figures: best case, most likely case and worst case.

The standard weighting comes from PERT. Expected time equals best case plus four times the most likely case plus worst case, divided by six (three-point estimation). Say a data migration takes 6 hours at best, 10 most likely and 20 if the export is a mess. The expected value is (6 + 40 + 20) / 6, which is 11 hours. That is not the 6 you would quote on a good day, and not the 20 that would lose the job.

The spread is also information. A task where best and worst are 8 and 9 hours is stable. A task where they are 4 and 20 is a warning, and you want to know that before you quote. Add the expected figures across every task and you have a bottom-up estimate made of parts you understand.

Step 3: Add a buffer and price vague scope as risk

Your task list covers the work you can see. A buffer covers the work you cannot: the file in the wrong format, the stakeholder who appears in week three, the quick tweak that reopens a finished section.

A reasonable buffer is 15% to 25% for work you know well and more for anything new. That range is a working convention, not a measured standard, so adjust it from your own history. Keep the buffer as a visible line you can explain, the way a builder prices contingency.

Vague scope deserves its own surcharge. When a brief is thin, you are being asked to quote a shape you cannot see, and the fair response is to price the uncertainty instead of absorbing it. Two ways to do that:

1. Raise the buffer. A clear brief might carry 15%. A brief that says "make it modern, you know what I mean" carries 30% or more, because the revision risk is real.
2. Sell a paid discovery phase first. For a fixed $500 to $1,000 you define the scope, produce a short spec and quote the build from something concrete. If a client will not pay for clarity, you have learned how the project would have gone.

For tactics that stop an agreed scope from drifting once work starts, see how to stop scope creep.

Step 4: Quote a range first, then a fixed number

Give a range before you give a single figure. A range tells the client something a fixed number hides: the price depends on decisions still to be made. "This lands between $4,000 and $6,000 depending on how many templates and revision rounds we settle on" is honest, and it starts a conversation about scope instead of your rate.

Once the scope is settled, turn the range into a fixed price. A fixed price only holds for the work described, so anything outside it is a change, quoted separately and not a favor.

Step 5: Write the scope next to the number

This step protects the estimate. A one-page statement of work turns "that was not included" from an argument into a line item. If the number lives in a chat thread and the scope lives in your head, you have nothing to point back to when the project grows. The statement of work guide shows what to include. Contracts and templates are starting points, so have a lawyer check yours before you rely on them.

For the bigger picture on rates, read the 2026 pricing guide, which compares hourly, fixed and value-based approaches.

How Delivvo keeps the estimate and the scope together

Delivvo turns the estimate into a document the client accepts before work starts, so the number you quoted stays on record.

1. Build the quote on the proposals page from your packages and add-ons. Put your discovery phase in as its own package, and price extra revision rounds as add-ons, so the options a client wants are visible and priced before the work begins.
2. Add the scope notes and assumptions to the quote or the contract, in your own words. Both can be edited line by line, so what you wrote in step 5 appears where the client signs.
3. On Pro, the one-page close lets the client choose packages, sign and pay the deposit in one visit. Delivvo then creates the client, the project, the contract, the invoice and the payment schedule for you.
4. Split the balance into a payment schedule of up to 12 payments tied to your task groups, so a long project does not rest on one invoice at the end.
5. Every quote, contract and invoice carries a verification code. If a client later says the price was different, you have a signed record with the IP, the device and an archived PDF.
6. Clients pay you directly through your own gateway. Delivvo takes 0%.

One detail other quoting tools skip is that the quote, contract and deposit live on one link. Your estimate is not sent as a PDF in one place and signed in another, so the number and the scope cannot drift apart.

The Free plan costs $0 with no card and covers 3 clients and 3 active projects, which is enough to run your next quote through it. See clients and projects for how a signed quote becomes a project.

Next, look at quotes and proposals or how the CRM fits around it.

FAQ