Plan paint or stain with confident roller coverage. Adjust for nap, texture, and coats easily. Download results as CSV or a neat PDF report.
| Scenario | Area | Coats | Texture | Coverage rate | Waste | Estimated needed |
|---|---|---|---|---|---|---|
| Garden fence (weathered) | 230 sq ft | 2 | Semi-rough | 350 sq ft/gal | 10% | ~1.6 gallons |
| Raised beds (smooth) | 90 sq ft | 1 | Smooth | 400 sq ft/gal | 8% | ~0.25 gallons |
| Shed wall (rough) | 140 sq ft | 2 | Rough | 325 sq ft/gal | 12% | ~1.1 gallons |
Most exterior paints and stains list an ideal spread rate. This calculator starts with that label value and then adjusts it for surface texture and roller nap. Smooth, primed boards often track close to the label. Weathered timber, end grain, and porous masonry usually absorb more, so the effective coverage decreases and purchase quantity rises. For stain, coverage can vary widely with wood species and prior coatings, so measure a small test panel before buying bulk. materials.
Texture drives the biggest swing in consumption. Semi-rough boards add an estimated 10% demand, while rough surfaces add about 20% before waste. Nap length also matters: thicker naps carry more coating into valleys and pores, improving fill but using more product per square unit. The estimator applies a modest nap factor around a 3/8 inch baseline.
Total material scales linearly with coats: doubling coats roughly doubles volume. Waste allowance captures tray loss, edging touchups, and small spills. For fences with many pickets and overlaps, 10–15% waste is common. For flat shed panels with clean edges, 5–10% may be sufficient. Round your purchase to the nearest container size available locally.
Beyond volume, the tool estimates roller reloads and rolling time to support scheduling. Reload counts depend on roller width and nap, because those influence how much coating is held per load. Time is based on a baseline rolling speed that is reduced on rough textures and scaled by a pace factor. Use the hours figure for rolling only, not prep.
Prep can exceed application time. Cleaning, sanding, patching, and drying are critical for adhesion outdoors. On bare or chalky surfaces, primer or conditioner reduces absorption and stabilizes the final finish, often improving real coverage. Plan for weather windows, shade management, and safe cleanup so your calculated quantities translate into durable results.
Use the spread rate printed on your paint or stain container. If a range is shown, choose the lower number for porous or weathered surfaces and the higher number for smooth, sealed surfaces.
No. Primer is not included in the coating total. If your project needs primer, estimate it separately using the primer label rate, then run this calculator again for the finish coats.
Rough surfaces have more surface area and pores. Coating fills valleys and fibers, reducing effective coverage per unit volume. The texture factor applies a conservative adjustment to reflect this behavior.
They are planning aids, not guarantees. Technique, edging, ladder work, wind, and drying delays can change productivity. Use the estimate to compare options and build a realistic work window.
Yes, adjust it to your situation. Increase waste for lots of edges, pickets, and touchups. Reduce it for wide, flat panels and experienced application with minimal tray loss.
Yes. Switch to metric, then enter panel length and height in meters and openings in square meters. The tool will estimate liters needed and provide the same adjusted coverage logic.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.