DIY vs Hire a Professional Calculator

It's a percentage penalty applied to your DIY base cost (materials + tools + time value) that estimates how likely you are to have to fix or redo the job because of mistakes. The calculator uses five fixed tiers tied to your self-rated skill level — 40%, 25%, 15%, 8%, and 2% for skill levels 1 through 5 — so a beginner's estimate absorbs a much bigger cushion for do-overs than an expert's. It's a heuristic multiplier, not a measured failure rate for any specific trade.

Your entered Estimated DIY Hours is multiplied by Your Hourly Wage to get a time value, which is added directly to materials and tools cost inside the DIY base cost. If you don't think your project time has a real dollar cost — say, it's a hobby you'd do anyway — set Your Hourly Wage to $0 and the calculator will compare only your out-of-pocket costs against the professional quote.

This happens when your hourly wage, DIY hours, or redo risk together outweigh the raw quote — for example, a low skill level on a long project stacks a large redo-risk penalty on top of an already sizable time value. In that case DIY Savings comes out negative, meaning the calculator is telling you hiring the professional is actually the cheaper option once your time and redo risk are priced in.

No — it only prices materials, tools, the time value of your DIY hours, and a skill-based redo-risk penalty. It has no input for injury likelihood, permit fees, or the opportunity cost of hours that could have gone to paid work instead, so those are worth weighing yourself alongside the numbers it produces.