Paint Calculator

• •Use the Paint Calculator when you need accurate results quickly without the risk of manual computation errors or unit conversion mistakes.
• •Use it to verify calculations made by hand or in spreadsheets — an independent check can catch errors before they lead to costly decisions.
• •Use it to explore how changing input parameters affects the output — a quick way to develop intuition and identify the most influential variables.
• •Use it when collaborating with others to ensure everyone is working from the same numbers and applying the same assumptions.

Nothing transforms a room faster than a fresh coat of paint, but buying too much wastes money and buying too little means an extra trip to the store -- where the new batch might not match perfectly. This calculator takes your room dimensions, subtracts window and door openings, multiplies by the number of coats, and divides by the paint coverage rate to give you the number of gallons needed. Most interior latex paints cover 300 to 400 square feet per gallon on smooth surfaces, with textured walls requiring more paint. Two coats are standard for a quality finish, especially when changing colors. Using this calculator ensures you purchase just the right amount for a professional-looking result.

• !Forgetting to multiply by the number of coats.
• !Using the coverage rate for smooth surfaces on textured walls.
• !Not accounting for primer as a separate purchase when painting over dark colors.
• !Overlooking ceiling area when planning a complete room repaint.