---
title: "Stair rise and run code: IRC limits and layouts"
description: "The 2021 IRC limits for stair risers (7-3/4\" max) and treads (10\" min), the 7-11 rule, and worked stair layouts for rises from 2' to 10'. Free PDF."
canonical: https://klmlabs.app/construction-calculator/stair-rise-and-run/
updated: 2026-11-07
---

# Stair rise and run code: 7-3/4" risers, 10" treads

Home stairs can have risers up to 7-3/4" high and treads at least 10" deep. The chart lays out stairs for rises from 2' to 10'.

Download the printable chart (PDF, US Letter, 1 page, 30 KB): https://klmlabs.app/construction-calculator/charts/stair-rise-and-run.pdf. Every number is worked out by Construction Calculator 1.1.1's own formulas.

## Stairs by total rise: 7-3/4" maximum riser and 10" treads

| Total rise | Risers | Riser height | Treads | Total run | Stringer | Angle |
|---|---:|---:|---:|---:|---:|---:|
| 2' 0" | 4 | 6" | 3 | 2' 6" | ≈ 3' 10-5/8" | 31° |
| 2' 6" | 4 | 7-1/2" | 3 | 2' 6" | 4' 2" | 36.9° |
| 3' 0" | 5 | ≈ 7-3/16" | 4 | 3' 4" | ≈ 5' 1-5/8" | 35.8° |
| 3' 6" | 6 | 7" | 5 | 4' 2" | ≈ 6' 1-1/4" | 35° |
| 4' 0" | 7 | ≈ 6-7/8" | 6 | 5' 0" | ≈ 7' 0-7/8" | 34.4° |
| 4' 6" | 7 | ≈ 7-11/16" | 6 | 5' 0" | ≈ 7' 4-7/16" | 37.6° |
| 5' 0" | 8 | 7-1/2" | 7 | 5' 10" | 8' 4" | 36.9° |
| 5' 6" | 9 | ≈ 7-5/16" | 8 | 6' 8" | ≈ 9' 3-5/8" | 36.3° |
| 6' 0" | 10 | ≈ 7-3/16" | 9 | 7' 6" | ≈ 10' 3-1/4" | 35.8° |
| 6' 6" | 11 | ≈ 7-1/16" | 10 | 8' 4" | ≈ 11' 2-7/8" | 35.3° |
| 7' 0" | 11 | ≈ 7-5/8" | 10 | 8' 4" | ≈ 11' 6-3/8" | 37.4° |
| 7' 6" | 12 | 7-1/2" | 11 | 9' 2" | 12' 6" | 36.9° |
| 8' 0" | 13 | ≈ 7-3/8" | 12 | 10' 0" | ≈ 13' 5-5/8" | 36.4° |
| 8' 6" | 14 | ≈ 7-5/16" | 13 | 10' 10" | ≈ 14' 5-3/16" | 36.1° |
| 9' 0" | 14 | ≈ 7-11/16" | 13 | 10' 10" | ≈ 14' 8-13/16" | 37.6° |
| 9' 6" | 15 | ≈ 7-5/8" | 14 | 11' 8" | ≈ 15' 8-3/8" | 37.2° |
| 10' 0" | 16 | 7-1/2" | 15 | 12' 6" | 16' 8" | 36.9° |

Treads are one fewer than risers. Lengths to the nearest 1/16" (≈ when rounded).

## The same rises at a 7" maximum riser and 11" treads (the 7-11 rule)

| Total rise | Risers | Riser height | Treads | Total run | Stringer | Angle |
|---|---:|---:|---:|---:|---:|---:|
| 2' 0" | 4 | 6" | 3 | 2' 9" | ≈ 4' 2-1/8" | 28.6° |
| 3' 0" | 6 | 6" | 5 | 4' 7" | ≈ 6' 3-3/16" | 28.6° |
| 4' 0" | 7 | ≈ 6-7/8" | 6 | 5' 6" | ≈ 7' 6-3/4" | 31.9° |
| 5' 0" | 9 | ≈ 6-11/16" | 8 | 7' 4" | ≈ 9' 7-3/4" | 31.2° |
| 6' 0" | 11 | ≈ 6-9/16" | 10 | 9' 2" | ≈ 11' 8-13/16" | 30.8° |
| 7' 0" | 12 | 7" | 11 | 10' 1" | ≈ 13' 0-7/16" | 32.5° |
| 8' 0" | 14 | ≈ 6-7/8" | 13 | 11' 11" | ≈ 15' 1-1/2" | 31.9° |
| 9' 0" | 16 | 6-3/4" | 15 | 13' 9" | ≈ 17' 2-1/2" | 31.5° |
| 10' 0" | 18 | ≈ 6-11/16" | 17 | 15' 7" | ≈ 19' 3-1/2" | 31.2° |

A gentler climb that takes more run. Lengths to the nearest 1/16".

## What does the code allow for stairs?

| What | Limit |
|---|---|
| Riser height | 7-3/4" max |
| Tread depth | 10" min |
| Even steps | risers within 3/8" of each other, and treads too |
| Nosing | 3/4" to 1-1/4" (none needed on treads 11" or deeper) |
| Headroom | 6' 8" min |
| Width | 36" min |
| One flight | 12' 7" of rise max |
| Handrail | 34" to 38" high, on flights of 4 or more risers |

From the 2021 IRC, R311.7. Local codes differ (New York allows 8-1/4" risers and 9" treads), so check yours.

## How do I work out stair steps?

1. Measure the total rise, finished floor to finished floor.
2. Divide by the maximum riser and round up: that is your number of risers.
3. Divide the rise by the risers for the riser height.
4. Treads are one fewer than risers.
5. Total run = treads × tread depth.

A 106-1/2" rise at 7-3/4" risers: 106.5 ÷ 7.75 = 13.7, so 14 risers of about 7-5/8", 13 treads and 10' 10" of run. The stringer is about 14' 7-7/8" long and climbs at 37.3°.

## Is an 8 inch stair riser too high?

Yes, for a home: the limit is 7-3/4". A 48" rise with 8" risers would be 6 risers; at 7-3/4" it needs 7 risers of about 6-7/8".

## What is the 7-11 rule for stairs?

Risers up to 7" and treads at least 11" deep: the code limit for most stairs outside homes. The second table uses it.

## What's the code for deck stairs?

The American Wood Council's deck guide uses the same 7-3/4" risers and 10" treads. Stairs are at least 36" wide, with a landing partway up past 12' of rise.

## Work out your own with Construction Calculator

- Risers, treads, run, stringer and angle from your total rise
- Share the layout as a one-page PDF
- Set your own limits for your local code

Download Construction Calculator on the App Store: https://apps.apple.com/us/app/fraction-feet-inch-calculator/id6816445977

Free to download, with in-app purchases. Every feature, the calculator included, needs the free trial or a purchase: Yearly US$9.99 a year with a 7-day free trial for eligible new subscribers, or Lifetime US$19.99 paid once (US prices). iPhone and iPad, iOS 17.0 or later. All the facts: https://klmlabs.app/construction-calculator/

## The facts this page states, with sources

As KLM Labs' fact record words them; the page may put them in its own words. Construction Calculator's facts page: https://klmlabs.app/construction-calculator/

- The stairs tool works out risers, treads, run and stringer, and shares the layout as a PDF. (Source: the app's source code (private).)
- Answers to the nearest 1/16", or any step from 1/2" to 1/64". (Source: the app's source code (private).)
- Every tool opens a short guide with a worked example. (Source: [Apple's app lookup](https://itunes.apple.com/lookup?id=6816445977&country=us).)
- IRC 2021 R311.7: riser not more than 7-3/4 in. (R311.7.5.1) and tread not less than 10 in. (R311.7.5.2), each varying by no more than 3/8 in. in a flight; headroom 6 ft 8 in. (R311.7.2); width 36 in. (R311.7.1); a flight rises no more than 12 ft 7 in. (R311.7.3); nosing 3/4 to 1-1/4 in., not required where treads are 11 in. or more (R311.7.5.3); a handrail on at least one side with four or more risers, 34 to 38 in. high (R311.7.8, R311.7.8.1). (Source: https://up.codes/viewer/colorado/irc-2021/chapter/3/building-planning (the 2021 IRC as adopted without amendments; read 2026-11-06).)
- IRC 2024 keeps the same stair limits, renumbered: R318.7.1 width 36 in., R318.7.2 headroom 6 ft 8 in., R318.7.3 rise 12 ft 7 in., R318.7.5.1 riser 7-3/4 in., R318.7.5.2 tread 10 in., R318.7.5.3 nosing 3/4 to 1-1/4 in. (none needed at 11 in.), R318.7.8 handrail with four or more risers, R320.2 handrail height 34 to 38 in. (Source: https://up.codes/viewer/texas/irc-2024/chapter/3/building-planning (Texas Windstorm Insurance Association Residential Code 2024, which adopts the 2024 IRC without amendments; read 2026-11-07).)
- Residential Code of New York State 2025 (the 2024 IRC with amendments) R318.7.5.1: risers not more than 8-1/4 in.; R318.7.5.2: treads not less than 9 in. (Source: https://up.codes/viewer/new_york/irc-2024/chapter/3/building-planning (read 2026-11-07).)
- IBC 2021 1011.5.2: risers 7 in. maximum and 4 in. minimum, treads 11 in. minimum; exception for Group R-3, dwelling units in R-2 and accessory Group U: 7-3/4 in. and 10 in. (Source: https://up.codes/viewer/colorado/ibc-2021/chapter/10/means-of-egress (read 2026-11-06).)
- AWC DCA 6-2015: 7-3/4 in. maximum riser, 10 in. minimum tread, stairs at least 36 in. wide, an intermediate landing when the total stair height exceeds 12 ft 0 in. (Source: https://web-media.awc.org/wp-content/uploads/2022/02/17210514/AWC-DCA62015-DeckGuide-1804.pdf (page 20 and Figure 27; read 2026-11-06).)

## More construction charts

- [Roof pitch chart: degrees, slope and rafter length](https://klmlabs.app/construction-calculator/roof-pitch-chart/): A roof pitch chart from 1/12 to 24/12: the angle in degrees, slope percent, plumb and seat cuts, and rafter length per foot of run. Free printable PDF.
- [Fraction to decimal chart: inches, millimeters and feet](https://klmlabs.app/construction-calculator/fraction-decimal-inch-chart/): A fraction to decimal chart for every 64th of an inch, with millimeters and decimal feet, plus inches to decimal feet. Free printable PDF, US Letter.
- [How many bags of concrete in a yard?](https://klmlabs.app/construction-calculator/concrete-bags-per-yard/): About 45 bags of 80 lb concrete make a cubic yard, 60 of 60 lb, 90 of 40 lb. A slab chart in yards and bags with 10% waste, as a free printable PDF.
- [How to calculate board feet](https://klmlabs.app/construction-calculator/board-feet/): A board foot is 144 cubic inches of lumber, 12" × 12" × 1". How to calculate board feet from nominal sizes, with a printable chart for 1x4 to 6x6.
- [How to calculate square footage from inches and fractions](https://klmlabs.app/construction-calculator/square-feet-from-feet-and-inches/): Multiply length × width in inches and divide by 144 for square feet. Worked examples with feet, inches and fractions, done exactly, and a printable chart.
- [Crown molding angles chart: miter and bevel settings](https://klmlabs.app/construction-calculator/crown-molding-angles/): Miter and bevel settings for 52/38 and 45/45 crown molding cut flat on a compound miter saw, for wall corners from 60° to 150°. Free printable chart.

All 7 construction charts: https://klmlabs.app/construction-calculator/guides/

## Sources

1. [International Code Council: 2021 IRC, Chapter 3, Building Planning (R311.7 stairways; the official text)](https://codes.iccsafe.org/content/IRC2021P2/chapter-3-building-planning)
2. [UpCodes: 2021 IRC Chapter 3 as adopted without amendments (R311.7.1 to R311.7.8, read in full)](https://up.codes/viewer/colorado/irc-2021/chapter/3/building-planning)
3. [UpCodes: 2024 IRC Chapter 3 as adopted without amendments (Texas Windstorm Insurance Association; R318.7 stairways, R320.2 handrail height)](https://up.codes/viewer/texas/irc-2024/chapter/3/building-planning)
4. [UpCodes: Residential Code of New York State 2025, Chapter 3 (R318.7.5.1 and R318.7.5.2 as amended)](https://up.codes/viewer/new_york/irc-2024/chapter/3/building-planning)
5. [UpCodes: 2021 IBC Chapter 10, Means of Egress (1011.5.2 riser height and tread depth)](https://up.codes/viewer/colorado/ibc-2021/chapter/10/means-of-egress)
6. [American Wood Council: DCA 6-2015, Prescriptive Residential Wood Deck Construction Guide (stairs, page 20)](https://web-media.awc.org/wp-content/uploads/2022/02/17210514/AWC-DCA62015-DeckGuide-1804.pdf)
7. [Fraction Feet Inch Calculator (Construction Calculator) on the App Store](https://apps.apple.com/us/app/fraction-feet-inch-calculator/id6816445977)

Last updated November 7, 2026.