Pressure Washing Estimate Calculator — built to win the bid.

Cold water pressure washing relies on PSI and flow rate (GPM) to break up dirt mechanically. It works well on routine maintenance cleans where buildup is mostly loose dirt, pollen, and light algae. Hot water units cut through grease, oil, and heavy grime chemically as well as mechanically, which is why auto shops, restaurant grease traps, and heavily stained commercial concrete are usually quoted at a slower production rate and a higher price per square foot even though the visible area is identical to a residential driveway.

The staining-level multiplier in the calculator above is a shortcut for this real difference: light buildup keeps the full rated production rate, moderate buildup assumes some slow passes and spot pretreatment, and heavy buildup assumes chemical dwell time, a second pass, and in some cases a hot water unit. If your equipment cannot reach hot water temperatures, heavily stained jobs may need a longer dwell time with a stronger degreaser instead — increase the condition multiplier or the chemical cost input to reflect that.

Track actual minutes per job against the estimate afterward. Over a few jobs per surface type, your own production rate and multiplier numbers will be more accurate than any published benchmark, including the ones in this guide.