Create bright, breathable coats for trunks and fences. Enter area, coats, and your preferred ratio. Get exact ingredients, then export records in seconds today.
Tip: If you are coating tree trunks, avoid saturating wet bark.
Sample rows show how export files may look.
| Date | Area | Coats | Ratio | Total Mix (L) | Lime (kg) | Water (L) | Additives |
|---|---|---|---|---|---|---|---|
| 2026-03-28 | 18 sqm | 2 | 1:2.5 | 5.00 | 0.79 | 3.57 | Salt |
| 2026-04-04 | 30 sqm | 1 | 1:3 | 4.13 | 0.57 | 3.09 | Salt, Binder |
| 2026-04-11 | 12 sqm | 2 | 1:2 | 3.30 | 0.61 | 2.20 | None |
This calculator estimates total mix volume, then splits it by your chosen ratio.
Mix outdoors, wear gloves and eye protection, and add water slowly to reduce splashes. Test on a small patch first, especially on young bark or painted surfaces.
Whitewash performance depends on film thickness, surface porosity, and weather. This calculator converts your area, coats, and coverage rate into a practical batch size so you can mix once, apply consistently, and reduce waste. Most garden surfaces fall between 6–12 sqm per liter per coat, while rough bark and unsealed masonry may need the lower end. For best consistency, sieve dry lime, mix to a smooth slurry, and keep it stirred during application.
The ratio is handled as volume shares, not weight. A 1:2.5 mix means 1 part lime slurry share and 2.5 parts water share in the final volume. Thicker mixes improve opacity and sun reflection, while thinner mixes spread faster and soak into pores. If you notice cracking after drying, increase water slightly or reduce coats per day.
Losses come from drips, brush loading, overspray, and material left in the bucket. A 10% allowance is a sensible starting point for small jobs, while 15–20% may fit windy sites or highly textured surfaces. Because the calculation applies waste after coats, the estimate scales correctly for multi-coat schedules and helps prevent mid-job remixing.
Additives are entered per liter of total mix so you can keep concentration consistent across different batch sizes. Salt can improve hardness as the film cures, while a small amount of PVA binder can increase adhesion on smoother surfaces. Copper sulfate is included as an optional antimicrobial component; keep rates conservative and avoid runoff into ponds or beds.
Documenting batches makes future maintenance predictable. Export the CSV for a log of area, ratio, and ingredient totals, or keep the PDF as a site worksheet. In orchards, many growers apply a bright coat before peak sun exposure to reduce heat stress and winter cracking, then touch up after heavy rains. Always test on a small section first, especially on young trees.
Use 8 sqm/L/coat for a first estimate. Rough bark, porous brick, or textured render may need 6–7. Smooth, sealed surfaces can reach 10–12. Adjust after a small test patch dries.
It is treated as volume share in the final mix. The calculator then converts the lime share to kilograms using your density input, helping you purchase the right amount of hydrated lime.
Waste accounts for drips, brush loading, uneven absorption, and leftover material. Adding 10–15% usually prevents shortages and reduces stop‑and‑start mixing that can cause inconsistent coverage.
Not always. Salt may help durability on exposed surfaces. A small binder dose can improve adhesion on smoother substrates. Skip additives for young bark or sensitive areas, and rely on good surface prep.
Yes. Enter the total area for trunks, posts, or walls and select coats. For trunks, avoid coating wet bark and keep the mix breathable. For walls, test compatibility with existing finishes.
Density varies by product and how you scoop it. The default is a practical approximation for hydrated lime. If you want higher accuracy, weigh a measured liter of your lime and update the input.
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.