Paint Calculator: How Much Paint Do I Need? (2025) (2025)

Calculating the right amount of paint for your project is crucial to avoid waste and ensure you don't run out mid-project. This guide will help you estimate your paint needs accurately. To get you started, the following table provides a quick reference for the coverage area of various paint types per gallon.

Paint calculator

Planning a painting project? Knowing how much paint you need ahead of time saves time and money. Our paint calculator simplifies the process, helping you estimate your paint needs accurately, so your next painting project is smooth from start to finish.

Here's how to use it:

1. Enter the room length, width, and height into the corresponding boxes.

2. Count and enter the total number of doors and windows in the room.

3. Mark the ceiling paint box if you plan to paint the ceiling as well.

4. Select the type of product you're using.

5. Click “Calculate” to see how much paint you need.

Factors that affect how much paint you need

A paint calculator provides an estimate, but actual coverage can vary. Don't forget to consider:

• Paint quality: Higher-quality paints provide better coverage.

• Color change: Drastic color changes may need additional coats.

• Wall texture: Smooth surfaces cover better than textured surfaces that use more paint.

• Porosity: Porous surfaces like brick need more paint.

• Surface preparation: Clean and primed surfaces help paint adhere better.

• Application method: Spraying uses 25% to 30% more paint than rolling.

• Environmental conditions: Temperature and humidity during application affect paint flow.

Paint cost per gallon by brand

Now that you've got a handle on how much paint to buy, the next question to ask is: How much does a gallon of paint cost? Prices can vary significantly depending on the brand, quality, and type of paint.

The following table provides a breakdown of what you can expect to pay per gallon from some top brands:

Planning your next paint project

Planning a successful painting project involves more than just picking a paint. These helpful tips will help you achieve a flawless finish:

Choose a paint color

Picking the right paint color for your project can be fun! Consider popular colors that fit your space's style, whether you're looking for the best exterior house paint colors or trendy interior shades. Choose a color that makes your space feel welcoming and beautiful.

Plan your project timeline

Before diving into your painting project, establish a clear timeline to keep everything on track. Consider factors like drying times, weather conditions (for exterior projects), and any necessary repairs or prep work. Having a well-defined schedule helps ensure your project stays on track.

Don't forget the trim and baseboards

Make sure to include your trim and baseboards in your painting plan. A fresh coat of paint on the trim and baseboards costs a bit more but greatly enhances the overall look of your space and creates a cohesive finish.

Hire a paint professional

Hiring a professional painter can elevate your paint project. They handle everything from prep to cleanup, saving you time and stress. Plus, you get expert color advice and guaranteed workmanship, which can boost your home's value and give you peace of mind.

FAQs about calculating paint needs

How much paint and primer do I need for one wall?

A typical wall is about 8 feet by 10 feet, or 80 square feet. For this size, you would need less than a quart of paint (less than a quarter of a gallon) and slightly more primer, as primer typically covers less area per gallon than paint does.

The exact amount of paint you need will vary depending on the type of paint you choose, the wall texture and porosity, and the application method.

How much paint do I need for the ceiling?

To calculate how much paint you need for a ceiling, follow these steps:

• Measure the length and width of the ceiling.

• Multiply the length by the width to calculate the square footage.

• Divide the square footage by the paint's coverage rate.

• Add 10% to your calculated amount for touch-ups or slight miscalculations.

Remember that the ceiling's surface can affect coverage, with textured ceilings needing more paint than smooth ones.

How much paint do I need for a room?

For an average 12-foot x 12-foot room with an 8-foot ceiling height, you'll need about 2 gallons of paint for two coats of coverage. This estimate includes walls but not the ceiling, and accounts for windows and doors.

How much paint do I need to paint my house?

To paint an entire house, calculate the total exterior square footage and divide by 300 to 400 to estimate the gallons needed. For a more precise estimate, use an online paint calculator or consult a professional.

Getting estimates from painters

When hiring a local interior painter or exterior painter near you, be sure to follow these suggestions:

• Ask the painter to visit and assess your space in person for accurate measurements and to point out any special needs.

• Request a detailed list of costs, including paint, labor, and any extra work needed.

• Verify the painter's background to ensure they can handle your specific project well.

• Collect estimates from several painters to compare prices and services offered.

• Make sure the estimate includes everything, from prep work to final cleanup.

Questions to ask your painter

Ask potential painters these questions to ensure you hire the best professional for the job:

• How many years have you been in business?

• Can you provide references or examples of previous work?

• Are you licensed and insured?

• What kind of paint do you recommend, and why?

• How do you prepare surfaces for painting?

• How long will the project take?

• How will you protect my property during the painting process?

• What kind of warranty or guarantee do you offer for your work?

• Can you provide a detailed breakdown of costs?

• What payment terms do you offer?