Here’s a basic cost estimator for house painting. To calculate the cost, consider factors like the size of the area to be painted, the type of paint, labour costs, and any additional expenses like primer or prep work. Here’s a general formula to estimate the cost:

Step 1: Determine the Wall Surface Area

1. Calculate Wall Area: Measure the length and height of each wall and multiply to get the wall area (in square feet).
   .
   Wall Area=Length×Height

    

2. Subtract Windows and Doors: Estimate areas of windows and doors, then subtract from the total wall area.

Step 2: Calculate Paint Needed

1. Coverage per Litre: Check the paint can for its coverage (usually around 300-400 sq ft per liter).

2. Number of Coats: Multiply total square footage by the number of coats needed.

   Liters Needed=Total Area×Coats/ Coverage per Litre

   Litres Needed=Coverage per Litre Total Area×Coats

Step 3: Calculate Paint Costs

1. Paint Cost: Multiply the litres needed by the cost per gallon of paint.

Step 4: Add Labor Costs

1. Labor Cost per Square Foot: Labor rates can vary (often around ₹10 – ₹45 per square foot). Multiply by the total wall area.

Step 5: Additional Costs

1. Primer and Other Supplies: Add costs for primer, brushes, tape, etc., if needed.

Example Calculation

Let’s say:

• Wall area is 1,200 sq ft.
• Paint coverage is 100 sq ft per litre.
• Cost per litre is ₹700.
• Labor cost is ₹8 per sq ft.
• One coat of paint is needed.

1. 1. Litres Needed:
      1200 sq ft/ 100 sq ft per litre ≈ 12 litre

      
      100 sq ft per litre 1200 sq ft ≈ 12 litres

1. Paint Cost:
   12 litres×₹700 per litre=₹840012 litres×₹700 per litre = ₹8400
2. Labor Cost:
   1200 sq ft×₹8=₹9600

   $$1200\text{ sq ft}\times ₹8\text{ per sq ft}=₹9600$$

3. Total Estimate:
   8400+9600=₹18000

   $$8400+9600=₹18000$$

So, the estimated cost would be ₹18,000.

Let me know if you’d like a custom estimator tool or more specific details!