A fixed project price feels fair to clients, because they know the total before work starts, but it only works for you when the price truly covers the hours the job will take. This estimator starts from your honest hour estimate and your normal hourly rate, then adds a buffer for the overruns that happen on almost every real project.
The three inputs are simple and each one matters. Hours are your best estimate of the work, including revisions and communication. Your hourly rate is the rate you would charge if the client paid by the hour. The buffer is a percentage that protects you when the work takes longer than planned. Together they produce a fixed price you can defend in a quote.
To use the tool, type each number into its box and press Calculate. The result appears below the button at once, and you can change any number and press Calculate again to test a new scenario. There is no account, no download and no payment, so you can try as many versions as you like before you quote a client. Start with your real numbers, not with round guesses, because the tool is only as honest as the inputs you give it.
How the maths works. It multiplies your estimated hours by your hourly rate to get a base price, then adds a buffer percentage of that base price to cover overruns, and the sum is your fixed project price.
A worked example makes it concrete. With the starting numbers of estimated hours 20, hourly rate ($) 50, buffer for overruns (%) 15, the tool returns these results: Base price (hours times rate) $1000.00; Buffer amount $150.00; Fixed project price $1150.00. Try changing one input at a time from there, and watch which result moves the most, because that input is the one worth getting right in your real quotes.
Who this helps. This calculator is built for freelancers who want to quote a fixed project price instead of charging by the hour. If you price work by feel or by copying what others charge, this tool gives you a number grounded in your own costs and time, which is a much stronger place to negotiate from.
Setting your numbers well matters more than the tool itself. Use last month of real records where you can: actual hours, actual travel, actual parts costs. Round numbers feel tidy but hide the truth, so prefer the slightly messy real figure. When a number is uncertain, run the tool twice, once with the low guess and once with the high guess, and quote from the middle of that range.
Practical tips. Estimate hours honestly by breaking the project into small tasks, because one big guess is almost always too low. Add a buffer even for simple projects, since clients change their minds and small jobs grow quietly. Raise the buffer for new clients or unclear briefs, where surprises are far more likely than with regular work. Compare the fixed price with your weekly rate, so a fixed quote never pays less than your normal week. Write the buffer into your quote as scope protection, not as a hidden extra the client discovers later.
Common mistakes to avoid. Quoting the base price with no buffer and then working extra hours for free when the project grows. Forgetting revision rounds, meetings and messages, which are real hours even when they feel small. Setting the buffer so high that the quote looks expensive, instead of explaining what the fixed price covers.
What this tool does not do. It gives an estimate from the numbers you enter, and it cannot know your local market, your skill level, or the exact scope of a job you have not described. Treat the result as a starting point for a quote, not as a promise of what a client will pay. This is general pricing help only, not professional financial advice, and for tax or legal questions you should speak to a qualified adviser.
Versión en español: Estimador de Precio de Proyecto por Horas