Paint Calculator

Calculate exactly how many litres of paint you need. Multiple rooms, surface types, African paint brands, primer calculation, and cost estimation — all free.

Multi-Room15+ African BrandsPrimer CalcCost Estimate
How to Use This Tool

1. Enter your room dimensions (length, width, height). 2. Set doors and windows to deduct from wall area. 3. Choose surface type and paint brand for accurate coverage. 4. Click "Add Another Room" for multi-room totals. 5. Hit Calculate to see litres needed, tin sizes, and cost.

Room Dimensions
Paint Options
Paint Estimate
Total Wall Area
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Paintable Area
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Paint Required (incl. 10% wastage)
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Recommended Tin Sizes

How to Calculate Paint for Your Walls in Africa

Whether you're painting a new build in Lagos, renovating a flat in Nairobi, or refreshing your Johannesburg home, knowing exactly how much paint to buy saves money and avoids running short mid-project. This calculator accounts for room dimensions, doors, windows, surface type, paint brand coverage rates, number of coats, and even primer requirements to give you the most accurate estimate possible.

Understanding Paint Coverage Rates

Paint coverage (spreading rate) varies by product and surface. Standard emulsion paints cover approximately 10-12 m² per litre on smooth plastered walls. Textured or rough walls absorb more paint, reducing coverage to 8-10 m² per litre. New bare plaster is the most absorbent at 6-8 m² per litre, which is why a primer coat is essential. Previously painted surfaces in good condition offer the best coverage at 10-14 m² per litre.

African Paint Brand Guide

Africa has a thriving paint manufacturing industry. In Nigeria, Dulux, Berger Paints, and CAP Plc dominate the market. South Africa's Plascon (owned by Kansai Paint of Japan) and Dulux SA are the leading brands. Kenya is served by Crown Paints, Basco, and Sadolin. Ghana has Azar Chemical Industries and Dolphin Paints. The Japanese firm Kansai Paint has expanded across the continent, making it the most truly pan-African brand.

Paint Types and When to Use Them

Emulsion paint is the standard choice for interior walls — it's water-based, low-odour, and easy to apply. Weathercoat or exterior paint is formulated to resist UV, rain, and temperature fluctuations common in African climates. Gloss or enamel paint is used for woodwork, doors, and window frames. Textured coatings provide a decorative raised finish and can hide minor wall imperfections.

Primer: When You Need It

Primer is essential on new bare plaster, concrete block walls that have never been painted, and when making drastic colour changes. Primer seals the porous surface, improves paint adhesion, and reduces the amount of topcoat needed. In Africa, where many construction projects involve painting newly plastered walls, skipping primer is one of the most common and costly mistakes.

Tropical Climate Considerations

African climates present unique challenges for painting. High humidity in coastal cities like Lagos, Mombasa, and Dar es Salaam promotes mould growth — use anti-fungal paint or add mould inhibitor to your paint. Extreme heat in Saharan and interior regions causes paint to dry too quickly, leading to cracking. In these areas, paint during cooler hours. Heavy seasonal rains in tropical regions mean exterior paint must be truly weatherproof — always use manufacturer-recommended exterior-grade products.

Frequently Asked Questions

How many coats of paint do I need?
Minimum 2 coats for a good finish. Use 3 coats when painting over a dark colour with a light one, on new/unpainted walls, or when using lower-coverage brands. Always apply primer first on bare surfaces.
Should I buy 4-litre tins or 20-litre drums?
20L drums are more economical per litre and better for large areas (2+ rooms). 4L tins are ideal for single rooms or touch-ups. This calculator shows the optimal combination to minimise waste and cost.
How do I calculate paint for an L-shaped room?
Use this calculator's L-Shape option. Enter the dimensions of both rectangular sections separately. The tool calculates the total wall perimeter and area automatically, accounting for the shared internal wall.
Do I need primer on previously painted walls?
Usually not, unless the existing paint is in poor condition (peeling, chalky) or you're making a drastic colour change (dark to light). On previously painted walls in good condition, 2 coats of your chosen paint is sufficient.
Which paint brands are best for African climates?
For exterior walls, Dulux Weathershield, Plascon SunCare, and Crown Weathercoat are formulated for harsh UV and tropical rain. For interior walls, any reputable brand's emulsion works well. In coastal areas, choose paints with anti-mould properties.
How much does painting cost in Africa?
Costs vary widely. In Nigeria, expect to pay ₦1,500-4,000 per litre for quality emulsion. In South Africa, R150-400 per litre. In Kenya, KSh 800-2,500 per litre. Labour costs are separate and typically charged per square metre or per room.
What's the standard door and window size for deduction?
Standard African door: 0.8m x 2.1m (1.68 m²). Standard window: 1.2m x 1.2m (1.44 m²). This calculator lets you select standard, small, or large sizes for more accuracy.