Pressure Washing Calculator – Time, Materials & Cost

MEASURE · PLAN · PRICE

Pressure washing calculator for time, materials and job cost

This free pressure washing calculator helps plan a patio, driveway or several separately measured surfaces. Enter the cleaning area and your effective productivity, or enter total cleaning hours directly. Optional water, detergent, joint sand and business costs create a printable estimate with visible assumptions.

The shortest route needs only a surface and a time method. You do not have to complete every pricing or material field. Different surfaces can have different productivity rates, and repeated copies or bulk measurements avoid entering similar areas one at a time.

How to use the calculator

1. Choose Metric or Imperial and enter one or more surface areas.
2. Deduct parts outside the cleaning scope and set copies or passes where relevant.
3. Enter effective single-pass productivity, using a surface override when needed, or choose total cleaning hours.
4. Add setup and packing time only if not already included.
5. Enable water, detergent or re-sanding only where they are in your job plan.
6. Optionally enter crew, equipment, travel and material costs.
7. Add markup, a minimum pretax job price and tax if appropriate, then calculate and print.

Physical area and cleaning workload

A 10 m by 5 m patio has 50 m² of physical area. Two cleaning passes create 100 m² of pass-adjusted workload, but the patio itself still covers 50 m². This distinction matters when estimating time and preparation materials.

Rectangle, triangle, circle and direct-area modes share the same calculation process. Triangle mode uses a perpendicular rise; circle mode uses diameter. Exclusions apply per copy. Split irregular surfaces into non-overlapping parts and avoid entering both a whole area and the same subdivisions.

Copies repeat an entire surface, including its passes and exclusion. Passes are a time-planning input, not a recommendation that a particular surface needs repeated high-pressure treatment. Choose a suitable method independently of the estimate.

Productivity and working time

Productivity mode divides each surface’s pass-adjusted workload by the entered square-area-per-hour rate. Use an observed effective rate for the actual equipment, surface condition and crew. A large flat patio, awkward edges and a heavily soiled driveway should not automatically share one generic speed.

For 50 m² at 25 m² per hour and one pass, cleaning time is two hours. Add half an hour for setup and packing and the planned job duration is 2.5 hours. If two people are paid for that whole duration, the estimate contains five person-hours.

Crew size does not automatically divide the job time. If another person or machine improves production, reflect that in the entered productivity or manual time. The calculator cannot infer whether a second worker is cleaning, moving equipment, controlling runoff or waiting.

Manual mode replaces the total productivity-derived cleaning time for all surfaces. It is useful when experience gives a better whole-job estimate than area alone. Setup time still adds once, so leave it zero if the manual figure already includes that work. Surface rates remain stored but are ignored in manual mode.

Optional water consumption

Water use depends on flow and how long it actually flows. The calculator multiplies cleaning time by the entered flow per minute and the water-on percentage, then adds separately entered extra water. Setup and packing hours are excluded.

Two cleaning hours at 8 litres per minute with water flowing for 75% of that time use 720 litres. Add 80 litres for an otherwise excluded rinse and the estimate becomes 800 litres. These are example inputs, not machine specifications.

Use actual flow or a defensible equipment figure. If several machines run at once, enter the relevant combined flow and time assumption. Do not add the same rinse under both cleaning time and extra water. This is a supply-use estimate, not a prediction of wastewater capture capacity or an approval for discharge.

Detergent purchase estimates

Detergent is optional because some jobs need none and product requirements differ. Enter the share of net physical area to be treated and the label coverage of ready solution. The calculator uses that treated area once, independently of cleaning passes.

Ready-solution yield explains how much final solution one unit of purchased product provides. A value of one represents ready-to-use product. If the manufacturer says one litre makes ten litres of final solution, enter ten. That differs from one litre plus ten litres of water, which would make eleven.

These fields calculate purchase quantities from supplied instructions. They do not recommend a chemical, concentration or mixing recipe. Equipment dosing can introduce additional dilution, so use data for the actual application method and follow product instructions. Kärcher’s published manuals similarly emphasise suitable approved detergents and the manufacturer’s dosage and safety information.

Matching usable stock reduces new purchases, which round up to complete containers. A purchase surplus should not be applied just because it was bought. If the specified treatment programme uses more than one application, use a coverage figure that represents that programme rather than assuming cleaning passes automatically describe chemical treatment.

Optional paving re-sanding

The re-sanding option estimates a specified joint material for the portion of net area that needs it. Enter the relevant share and material usage in kg/m², then bag size and stock. It is not automatically appropriate for every paving type, and the calculator does not prescribe the product or application conditions.

For 20 m² requiring 2 kg/m², the requirement is 40 kg. With 5 kg available and 25 kg bags, buy two bags. That leaves some purchase surplus. Joint dimensions, paving condition and product instructions determine the real rate.

Re-sanding labour is not automatically added to cleaning duration. Include it in the entered time or separately assessed other costs, without counting it twice. These technical sand inputs remain clearly labelled kg/m² and kg in both measurement systems.

Costs, markup and minimum job charge

Labour cost uses planned job duration multiplied by paid crew and cost per person-hour. Equipment running cost uses cleaning time only. Add travel, mobilisation, disposal and other separately assessed expenses where they are not already in another rate.

The cost total includes enabled new material purchases and water cost. Water pricing remains per 1,000 litres, even when the displayed volume is US gallons, so the input basis stays explicit. Currency selection changes display symbols without an exchange-rate conversion.

Markup adds a percentage to the total cost. The minimum job price then acts as a floor on that pretax selling price. For example, £100 cost with 20% markup gives £120; a £150 minimum raises it to £150, not £270. The result shows the £30 minimum-charge uplift separately. Tax applies afterwards.

Minimum charges can account for the commercial reality of small jobs, but they do not replace checking your costs. Markup is not profit margin. Use consistent pretax prices so the optional tax is not duplicated.

Frequently asked questions

Manufacturer reference

See the Kärcher G 3800 operating guidance for an example of equipment-specific detergent instructions. Follow the manual for your actual machine and the label for the product used.

Related calculators

• Job Price Calculator

  Combine wider maintenance costs.

• Hourly & Day Rate Calculator

  Review your business labour rates.

• Decking Calculator

  Plan separately assessed deck repairs.

• Turf Calculator

  Estimate a separate lawn project.