Seattle Concrete Cost Calculator
Estimate a 2026 Seattle concrete patio or slab with a broom, exposed-aggregate, or stamped or colored finish, and breaking out an old slab. Prices include excavation, a compacted gravel base, the concrete and the finish. A 300 sq ft broom-finish patio comes to about $2,850.
Planning pavers, sod or planting around the new concrete? Run the landscaping calculator. Weighing a raised deck instead? Run the deck calculator. For a firm number, request a quote.
Your Estimate
Pick what you need and click Calculate
Each item shows its installed price per unit
What this calculator captures
Installed price from this calculator for a 300 sq ft patio, with excavation, a compacted gravel base, the concrete and the finish. Breaking out an old slab is priced in the calculator above.
- Broom finish
- About $2,850
- Exposed aggregate
- About $3,990
- Stamped or colored
- About $4,275
About $9.50 per sq ft. The surface is brushed for grip.
About $13.30 per sq ft. The top layer is washed back to show the stone.
About $14.25 per sq ft, stamped with a pattern or colored.
Using this calculator
What does each price include?
The broom-finish, exposed-aggregate and stamped or colored prices are per square foot installed, and include excavation, a compacted gravel base, the concrete and the finish. Breaking out an old slab is priced per square foot of a 4-inch slab and covers sawing and breaking it out.
Is there a job minimum?
Yes, $1,500. When a job totals less, the difference is added as its own Mobilization & Job Minimum line, so the line items still add up to the total. A 300 sq ft broom-finish patio ($2,850) clears it; a 150 sq ft broom-finish pad ($1,425) prices at $1,500.
Does it price replacing an old patio?
Yes. Switch on both the new concrete and the old slab break-out, and set each area. Breaking out 300 sq ft of old 4-inch slab and pouring a 300 sq ft broom-finish patio comes to about $4,038.
How are these prices set?
Each item's price is set against the lowest installed price that registered Seattle-area contractors publish on their own websites for the same scope, dated 2025 or 2026, at about 95% of it. Lead-generation and pricing-template sites never set a price, and neither do Kolmo's own quotes. The full method is at /how-estimates-work.
What doesn't the calculator price yet?
This calculator prices patios and slabs. Steps, walkways, resurfacing and garage slabs are not in it yet; they are quoted after a walkthrough.
Keep planning
Continue the planning once you have a number.