Why Calculate Exterior Paint Accurately?
Repainting house exterior siding is a significant investment. Calculating exact paint requirements before visiting the store ensures smooth execution: - Avoid Color Batch Variations: Buying paint all at once guarantees color consistency across batch lots. - Account for Surface Porosity: Rough stucco and bare cedar consume significantly more paint than smooth vinyl or pre-primed fiber cement. - Separate Body and Trim: Siding (satin/flat finish) and trim/doors (semi-gloss finish) require different paint formulas and separate gallon purchases.
Exterior Paint Coverage Formulas
\[\text{Net Siding Area} = \text{Gross Exterior Area} - \text{Openings (Windows/Doors)}\] \[\text{Soffit \& Trim Area} = \text{Trim Linear Feet} \times 1.0 \text{ ft (Avg Width)}\] \[\text{Body Gallons} = \left( \frac{\text{Net Siding Area}}{\text{Coverage Rate (sq ft/gal)}} \right) \times \text{Coats}\] \[\text{Trim Gallons} = \left( \frac{\text{Soffit \& Trim Area}}{350} \right) \times \text{Coats}\] \[\text{Total Paint Cost} = (\lceil \text{Body Gallons} \rceil + \lceil \text{Trim Gallons} \rceil) \times \text{Price Per Gallon}\]Exterior Paint Requirements by House Size (2 Coats)
| Home Size / Type | Net Wall Area | Siding Material | Body Gallons | Trim Gallons | Est. Material Cost ($45/gal) |
|---|---|---|---|---|---|
| 1,200 sq ft Single Story | 1,200 sq ft | Wood Clapboard | 7 gal | 2 gal | $405.00 |
| 1,800 sq ft Two Story | 1,600 sq ft | Vinyl Siding | 8 gal | 2 gal | $450.00 |
| 2,500 sq ft Two Story | 2,200 sq ft | Stucco / Masonry | 18 gal | 3 gal | $945.00 |
| 3,200 sq ft Executive Home | 3,000 sq ft | Fiber Cement | 18 gal | 4 gal | $990.00 |
Step-by-Step Exterior Painting Guide
- Measure Exterior Walls: Measure total length of exterior walls and height from foundation to roofline.
- Deduct Openings: Measure windows, entry doors, garage doors, and sliding glass doors to subtract non-painted square footage.
- Select Siding Material: Choose your siding type to apply proper coverage per gallon rates (e.g. 400 sq ft/gal for vinyl vs 250 sq ft/gal for stucco).
- Input Trim Length: Add up linear feet of eaves, soffit overhangs, fascia, corner boards, and window trim.
- Set Coat Count & Price: Select 2 coats for standard durability and enter your paint price per gallon.
- Review Gallon Estimates: Buy rounded full gallon cans for siding body and trim colors.
Frequently Asked Questions
How many gallons of paint do I need for a 2,000 sq ft house?
A 2,000 sq ft two-story house typically has around 2,200 to 2,500 sq ft of exterior wall area. For 2 coats of paint, you will need approximately 12 to 15 gallons for the siding body and 2 to 3 gallons for trim.
How much exterior paint does 1 gallon cover?
One gallon of exterior acrylic latex paint covers 350 to 400 sq ft on smooth vinyl or painted wood, but only 200 to 250 sq ft on rough stucco, unsealed brick, or weathered wood.
Should I apply 1 coat or 2 coats of exterior paint?
Two coats are strongly recommended for exterior paint jobs to provide UV protection, weather resistance, and color uniformity. One coat is acceptable only for exact-color touch-ups over intact paint.
How do I calculate trim and soffit paint separately?
Multiply total linear feet of trim by 1 foot average width to estimate trim square footage. Trim usually requires 1 to 3 gallons of semi-gloss exterior paint depending on house size.
How much does professional exterior paint cost per gallon?
High-quality 100% acrylic exterior latex paint ranges from $40 to $70 per gallon. Premium grade paints with self-priming formulas can cost up to $85 per gallon.
Does stucco require more paint than wood siding?
Yes. Stucco is highly porous and textured, absorbing up to 40% more paint than smooth lap siding. First coats on unpainted stucco require elastomeric paint or masonry primer.
Is my personal data stored when using this calculator?
No. All calculation algorithms run directly inside your web browser without saving personal data.