Wood Protection Calculator: How Many Litres Do You Really Need?
Impregnants and oils for wood.
- 1Dimensions
- 2Result
Material
Wood protection
Typical room
What we calculate
Openings (doors and windows)
Getting the right amount of wood preservative, stain or decking oil before you start saves you two trips to the shop. Our calculator uses real coverage rates from the products we stock: wood impregnant typically covers around 5 m² per litre, wood stain (lazură) around 12 m², and a conservative fallback of 8 m² per layer when the exact product spec is unknown. Most exterior applications need two coats, and we add 10% on top for waste. Type in your area and get an honest number in seconds.
Whether you're treating a garden fence, a pergola or a hardwood deck, the formula is the same. Surface area (m²) multiplied by number of coats, divided by coverage rate, plus that 10% buffer. For 20 m² with two coats at 8 m²/L, that's 20 × 2 ÷ 8 = 5 L, then add 0.5 L for waste - so you buy 5.5 L. Simple, no guesswork.
What the Calculator Covers
Wood protection covers three main product types you'll see on our shelves:
- Impregnant (preservative) - deep-penetrating, colourless or lightly tinted. Typically 5-8 m² per litre. Best for new timber, fences, structural wood.
- Lazură (wood stain) - semi-transparent, pigmented, better UV blocking. Around 10-15 m² per litre because it sits closer to the surface.
- Decking oil - for horizontal surfaces like terraces. Coverage 6-10 m² per litre; rough or sawn timber absorbs more than planed.
Softwoods (pine, spruce) generally absorb 20-30% more product than hardwoods. If your timber is rough-sawn rather than planed, budget toward the lower end of the coverage range. The calculator defaults to a conservative 8 m²/L to keep you from running short.
Brands available at Colorista.md include Vidaron, Sadolin, Eskaro and Supraten - each product page lists its exact coverage so you can re-run the calculation with the precise figure.
How to Calculate Coverage - Step by Step
The formula has four steps and takes about two minutes.
Step 1 - Measure total surface area (m²). For a fence multiply height by total length. For decking multiply width by length. Include all sides of posts and rails if you're treating them too.
Step 2 - Choose number of coats. Two coats is standard for exterior wood. New, very porous timber sometimes benefits from three. Interior wood in covered areas can be fine with one.
Step 3 - Divide by coverage rate. Use the figure from the product datasheet. If you don't have it, use 8 m²/L (impregnant) as a safe default.
Step 4 - Add 10% wastage. Multiply your result by 1.10. Round up to the nearest available pack size.
Example: 20 m² deck, 2 coats, impregnant at 8 m²/L: 20 × 2 ÷ 8 = 5 L × 1.10 = 5.5 L. Buy a 6 L pack or two 3 L cans.
Why Buy at Colorista.md
We stock Vidaron, Sadolin, Eskaro and Supraten wood protection lines at our Chisinau warehouse with delivery across Moldova. Every product page shows the manufacturer's coverage rate - the same number this calculator uses. No invented figures, no outdated specs.
Order online and we'll confirm availability the same day. Questions about which product suits your specific timber? Call or chat and our team gives you a straight answer based on what we actually carry.
Frequently asked questions
How much wood stain do I need per square metre?
It depends on the product type. Wood stain (lazură) typically covers 10-15 m² per litre, while a penetrating impregnant covers 5-8 m² per litre. Rough or sawn timber absorbs more than planed timber, so use the lower end of the range if unsure. Our calculator defaults to 8 m²/L as a safe starting point.
How many coats of wood preservative should I apply?
Two coats is the standard recommendation for exterior wood. Apply the first coat and let it absorb fully - check the product label for drying time, usually 4-24 hours depending on temperature. The second coat seals the surface and improves UV and moisture resistance. For very porous new timber, a third coat can help.
How do I calculate how much wood stain I need for a fence or deck?
Multiply the total surface area (m²) by the number of coats, then divide by the coverage rate (m²/L) shown on the product label. Add 10% for wastage. Example: a 30 m² fence, 2 coats, at 10 m²/L needs 30 × 2 ÷ 10 = 6 L, plus 0.6 L waste, so buy 7 L. Use our calculator above to get the number instantly.