Calculator Inputs
Example Data Table
| Example | Area (m²) | Surface | Soil | Solution | Ready mix (L) | Concentrate / Powder | Water (L) |
|---|---|---|---|---|---|---|---|
| A | 20 | Concrete | Medium | General cleaner, 4% | 4.32 | 0.173 L concentrate | 4.147 |
| B | 35 | Pavers | Heavy | Oxygen bleach, 35 g/L | 9.63 | 336.9 g powder | 9.63 |
| C | 15 | Natural stone | Light | Vinegar, 10% | 3.47 | 0.347 L vinegar | 3.119 |
| D | 50 | Concrete | Heavy | Pressure detergent, 4.5% (2 passes) | 22.40 | 1.01 L concentrate | 21.39 |
Formula Used
How to Use This Calculator
- Pick your unit system and area method.
- Enter dimensions or total patio area.
- Select surface, soil level, and solution type.
- Keep default strength, or set a custom one.
- Adjust waste and applications for your workflow.
- Press calculate to view the mix above the form.
- Download CSV or PDF for job notes and printing.
Coverage Rates by Surface
Default application rates estimate how much ready-to-use mix you need. Concrete uses 0.20 L/m² per pass, while pavers use 0.25 L/m² because joints absorb more liquid. Natural stone averages 0.22 L/m², wood decks 0.18 L/m², and composite boards 0.17 L/m². In imperial terms, 0.20 L/m² is about 0.49 gal per 100 ft².
Strength Profiles for Common Cleaners
Recommended strength bands scale with soil level. General concentrate defaults to 2%, 4%, or 6% for light, medium, and heavy soil. Pressure washer detergent defaults to 1.5%, 3.0%, or 4.5%. Bleach solution stays conservative at 1.0% to 2.0%, vinegar ranges from 10% to 30%, and oxygen bleach powder uses 15 to 35 g/L. Use custom strength when a label specifies a different ratio.
Optimizing Dwell Time and Rinsing
Performance depends on contact time, not only concentration. Many patio cleaners work with a 5–10 minute dwell window, followed by thorough rinsing. Use two applications when stains are layered: the first loosens grime, the second targets remaining marks. Keep surfaces damp so solutions do not dry in direct sun.
Batch Planning for Tanks and Buckets
Large areas often exceed one sprayer fill. The calculator converts your tank size into liters and then computes full fills plus a remainder. If you need 22.4 L and your tank is 10 L, you will make two full fills and one partial fill of 2.4 L. Consistent batching prevents “strong first, weak last” mixing errors.
Reducing Waste and Runoff
Waste allowance covers overspray, pooling, and rough texture. The default buffer is 8%, but you can set 0% for controlled bucket scrubbing or up to 50% for uneven pavers. Measure area, pre-sweep debris, and apply evenly to reduce runoff. Lower waste means fewer refills and steadier dwell times. Record your settings for repeat jobs and faster planning on future maintenance days.
FAQs
How does the coverage override affect results?
It replaces the default surface rate. Higher coverage increases ready-to-use volume, which also increases concentrate or powder. Use it when your sprayer output, nozzle pattern, or surface porosity differs from the defaults.
Which solution type should I choose for my patio?
Pick the product you actually have and follow its label. Use gentler options for sensitive stone and painted surfaces. For heavy algae or mold, choose a profile that matches the cleaner’s active ingredient and recommended dilution.
When should I use custom strength?
Use custom strength when the manufacturer specifies a ratio that differs from the presets, or when you are testing a small area. Start lower on delicate surfaces, then increase only if cleaning performance is insufficient.
How do I handle an irregular patio shape?
Break the patio into rectangles or triangles, calculate each area, and add them. Alternatively, measure total area directly if you already have a site plan. Then apply the same coverage and strength settings to the combined area.
What does the refill plan mean?
It shows how many full tank fills you will mix, plus the final partial amount. This helps you pre-measure concentrate or powder for each batch and avoids guessing halfway through the job.
Is the bleach profile safe for nearby plants?
Bleach can damage foliage and soil biology. Pre-wet plants, prevent runoff into beds, and rinse thoroughly after cleaning. Never mix bleach with acids or ammonia, and consider oxygen bleach for plant-adjacent areas.