Stair Calculator
Calculate stair risers, treads, stringer materials, cut layout with angles, and labor — with IRC code checks and pre-code override for older homes.
This is an estimate, not a bid or contract. Every job has unique conditions — access, structure, moisture, code — that software cannot account for.
Use at your own risk. Pinnacle Designs, LLC is not liable for bids, losses, or code compliance based on calculator output. You are responsible for verifying all numbers before use.
Terms of Service (limitation of liability & your responsibilities)
Always verify local building codes. Supplier prices vary by region. Add waste for cuts, mistakes, and damaged material.
Typical residential stair code (IRC R311.7 — Stairways (typical US residential)):
- Minimum tread depth: 10" (nosing to nosing). Without a nosing, many jurisdictions require 11".
- Maximum riser height: 7.75" (62/8").
- Minimum riser height: 4".
- Uniformity: Risers and treads within a flight may vary no more than 0.375" (3/8").
- Minimum clear width: 36" for interior residential stairs.
- Headroom: 80" (6′-8″) minimum above tread nosing.
Local amendments vary. Pre-1970s and rural homes often pre-date current code — use custom dimensions when matching existing work.
Job Site Market (ZIP & Region)
Enter the job ZIP — not your shop — to load typical local labor and material defaults. Useful when bidding out of town or out of state.
Most U.S. ZIPs auto-select a region. Unknown ZIPs — pick the closest market manually.
Typical U.S. contractor rates, loaded ~5% above market average — adjust for your bid.
National Average — typical contractor labor ~$57.75/hr
Typical labor rates align with the national average.
Defaults load ~5% above typical market averages — a conservative benchmark when clients compare your bid. Edit any rate below for your actual numbers.
Regional defaults update labor, materials, markup, and tax in this calculator. Your job ZIP and region are saved across all calculators — change ZIP when you switch to a different job site.
Estimate — not a bid. This is an estimate, not a bid or contract. Every job has unique conditions — access, structure, moisture, code — that software cannot account for. Each job is unique. Final prices may vary based on site conditions, scope, materials, labor, and your local market. Use at your own risk. Pinnacle Designs, LLC is not liable for bids, losses, or code compliance based on calculator output. You are responsible for verifying all numbers before use. Full terms
Stair Dimensions
Floor to floor
Code max 7.75" — actual 7.385" with 13 risers
Code minimum 10" nosing to nosing (11" if no nosing)
Interior code minimum 36" clear width
Stringer & Tread Materials
Stringer Cut Layout
Hover or tap the i icons to learn each part · click drawing to zoom
Save stores this on your device · Add to Estimatesends material & labor lines to the Full Job Estimator
Material List / Shopping List
- 2×12 Sawn Lumber Stringer3
- Construction Pine / SPF — treads12
- Risers13
- Stringer board length159.2" each
Results Summary
Recommended Client Price
$1,543.28
Estimate — not a bid
Numbers from this tool are planning estimates only. They are not a contract, quote, binding bid, or professional advice. Every job carries its own challenges — hidden damage, tight access, moisture, local code, and scope details — that no calculator can see.
Each project is different. Access, existing conditions, code requirements, material choices, and your local market all affect the final price. Use these figures as a starting point — your actual price may vary.
By using this tool you agree you will not rely on it as a final bid without your own verification. See our Terms of Service for limitations of liability and your responsibilities.
Cost Breakdown
How this was calculated
- Risers = total rise ÷ desired riser height (rounded)
- Code check: tread ≥ 10", riser ≤ 7.75" (IRC R311.7)
- Stringer cut length & angles computed automatically
- Materials: pick stringer and tread/riser types
- Labor: hours × rate (adjusted for stringer complexity)