Measure each fence section and side
Measure the horizontal length and average height of each section, then multiply length by height for one face. Keep sections separate when heights or construction styles change. Decide whether the project includes one face or both: a 100-foot-long, 6-foot-high fence is 600 square feet on one face and 1,200 square feet for two faces before adjustments.
Measure gates as their own rectangles if they will be stained. Subtract only true openings that contain no wood. Posts, caps, kickboards, and exposed edges add area, while widely spaced pickets reduce the solid face. The fence stain calculator can account for fence style, but a direct board count is more accurate for an unusual design.
- Record each height change instead of using the tallest height everywhere
- Count both faces only when both are accessible and included in the job
- Add gates, posts, caps, and trim that receive the same product
- Keep a sketch so the crew knows which neighbour-facing sections are included
Use the coverage rate on the selected stain
Do not estimate from a generic “stain” rate. Coverage changes with product chemistry, application method, wood species, surface texture, porosity, and whether the boards are new, weathered, or previously coated. Use the rate printed on the current product label or technical sheet for the relevant surface condition.
Rough-sawn faces, end grain, cracks, and dry weathered boards can absorb more than smooth sealed wood. Spraying can also create transfer loss, especially on open pickets. Apply a measured test area when the wood is unusually porous, then compare actual use with the estimate before purchasing the remainder.
- Keep the calculator rate in the same units as the product label
- Use the label’s rough-surface range when that matches the fence
- Do not thin stain to stretch coverage unless the manufacturer permits it
- Round the final purchase to available container sizes
Calculate coats from the product system
If a hypothetical label lists 200 square feet per gallon for one coat, a measured 1,200-square-foot two-sided fence would require 1,200 ÷ 200 = 6 gallons for that coat before waste and detail work. This is an arithmetic example, not a recommended coverage rate; replace 200 with the value for your product and substrate.
Do not simply double the quantity until you confirm that the product calls for two coats. Some penetrating systems specify one saturating application, some use wet-on-wet passes, and film-forming products may require separate coats. The exterior stain coat guide explains how to read that decision.
Prepare for even absorption
Clean dirt, biological growth, and loose fibres using methods compatible with the wood and coating. Remove failing previous finish where required, rinse away cleaning residue, and allow the fence to reach the moisture condition specified by the stain maker. Staining damp wood can reduce penetration or trap moisture.
Protect plants, masonry, siding, and neighbouring property from cleaner and overspray. Stir the stain as directed and mix containers together when colour uniformity matters. Work complete board lengths or panel sections while maintaining a wet edge; stopping in the middle of a board can leave lap marks.
Choose a workable weather window
Follow the label’s limits for air and surface temperature, humidity, rain-free time, direct sun, and drying before evening dew. In many Canadian regions, spring and autumn can bring cool nights even after a mild afternoon, so check the full application and curing window rather than only the daytime high.
After the fence dries, record the product, colour, batch, application date, and areas completed. Inspect exposed tops, horizontal caps, end grain, and sprinkler-facing sections more often because they can weather differently. Maintenance should be triggered by the product’s condition and manufacturer guidance, not an arbitrary calendar interval.