Deck Stair Height Calculator

Aspect	Measurement / Description
Standard Rise	7 to 7.75 inches (typically)
Maximum Rise	Varies by local building codes
Comfortable Rise	7 to 7.25 inches (commonly preferred)
Standard Run (Tread)	10 to 11 inches (typically)
Maximum Run	Varies by local building codes
Comfortable Run	10 to 11.25 inches (commonly preferred)
Recommended Total Height for One Step	4 to 7.75 inches
Maximum Total Height for One Step	Varies by local building codes
Minimum Number of Steps for a Landing-less Staircase	3 (to avoid a landing)
Maximum Stair Height without a Landing	Usually up to 12 feet
Ideal Riser and Tread Combination	Around 7-inch riser and 11-inch tread (for a 25-inch total)
Maximum Span for a 2×12 Stringer	Up to 6 feet (varies by code and lumber grade)
Required Spacing between Stringers	Approximately 16 inches on center
Recommended Width for Outdoor Steps	36 to 48 inches

FAQs

How high should deck stairs be?

The height of deck stairs is typically determined by the total height from the ground to the deck surface. The stairs should be divided into a series of equal riser heights to ensure safety and comfort during ascent and descent.

What is the standard rise and run for deck stairs?

The standard rise for deck stairs is usually around 7 to 7.75 inches, and the run (tread) is typically 10 to 11 inches. These dimensions may vary based on local building codes and individual design preferences.

What is the formula for deck stairs?

The formula for deck stairs involves dividing the total height (in inches) by the desired riser height to determine the number of steps needed. The run is then determined based on the riser height and total run.

How many steps are in a 4-foot-high deck?

To calculate the number of steps for a 4-foot-high deck, divide the total height (48 inches) by the desired riser height (e.g., 7 inches). The result will give you the approximate number of steps required.

What is a comfortable rise and run for deck stairs?

A comfortable rise for deck stairs typically falls within the range of 7 to 7.75 inches, and a comfortable run (tread) is usually 10 to 11 inches. These dimensions ensure a gradual and natural stride for most people.

How tall can deck stairs be without a landing?

The International Residential Code (IRC) states that deck stairs can typically rise to a maximum height of 12 feet without requiring an intermediate landing. However, local building codes may have different regulations, so it’s essential to check with your local authorities.

Is an 8-inch step too high?

An 8-inch step may be considered too high for some people, as it exceeds the comfortable rise range of 7 to 7.75 inches. Steps that are too high may cause discomfort and difficulty while using the stairs.

What is the 18-rule for a staircase?

The 18-rule for a staircase refers to the sum of two times the rise (height) and the run (tread) of each step, which should be approximately 18 inches. For example, if the rise is 7 inches, the run should be around 11 inches, and the total would be 18 inches.

What is the ideal stair riser and going?

The ideal stair riser height is between 7 and 7.75 inches, while the ideal stair going (tread depth) is between 10 and 11 inches. These dimensions provide a comfortable and safe stair design.

Should stair stringers be 2×10 or 2×12?

Stair stringers are typically made of 2×12 lumber for added strength and stability, especially for outdoor deck stairs. The wider stringer provides better support for the treads and risers.

How do you calculate stringers for deck stairs?

To calculate the number of stringers needed for deck stairs, divide the total stair width (in inches) by the desired spacing between stringers (usually 16 inches). Round up the result to the nearest whole number. For example, for a 40-inch stair width, you would need three stringers (40 inches ÷ 16 inches = 2.5, rounded up to 3).

What is the best stair formula?

The most commonly used stair formula is the “7-11” formula, where the riser height is 7 inches, and the tread depth is 11 inches. However, other combinations within the comfortable range may also be used based on local building codes and individual preferences.

How many stringers do I need for 40-inch stairs?

For 40-inch stairs, you would typically need three stringers, spaced at approximately 16 inches apart. However, the number of stringers needed may vary depending on local building codes and the design of your stairs.

How many steps do I need for a 36-inch high deck?

To determine the number of steps for a 36-inch high deck, divide the total height (36 inches) by the desired riser height (e.g., 7 inches). The result will give you the approximate number of steps required.

Do deck stairs need risers?

Deck stairs may or may not have risers, depending on the design and local building codes. Open riser stairs are common for outdoor decks as they allow water to drain through, reducing the risk of rot and moisture issues.

Do deck stairs have to land on concrete?

Deck stairs do not necessarily have to land on concrete. They can also land on a sturdy landing platform made of pressure-treated wood or other suitable materials that meet local building codes.

What is the minimum landing for deck stairs?

The minimum landing size for deck stairs typically needs to be at least as wide as the stairs and extend a minimum of 36 inches in the direction of travel. The length may vary based on local building codes.

How high can deck stairs be without railing?

In most jurisdictions, deck stairs that rise to a height of 30 inches or more generally require a handrail on at least one side. However, local building codes may have different requirements, so it’s essential to check with your local authorities.

Does the landing count as a step?

No, the landing does not count as a step when determining the number of steps required for a staircase. It is a flat platform that provides a resting area between flights of stairs.

How far apart should deck posts be?

The spacing between deck posts depends on local building codes and the structural requirements of your deck. As a general guideline, the maximum distance between deck posts is usually around 6 to 8 feet.

What is the best size step for stairs?

The best size step for stairs is typically within the comfortable range of 7 to 7.75 inches for the riser height and 10 to 11 inches for the tread depth.

How many inches is code for a step?

Building codes may vary, but a common code requirement for the riser height of interior stairs is between 4 and 7.75 inches. Exterior stairs may have different code requirements, so it’s crucial to follow local building codes.

How high can a porch step be?

The height of a porch step may vary based on local building codes and individual design preferences. As a general guideline, porch steps often have a riser height of 4 to 7.75 inches.

What is the golden rule for stairs?

The “golden rule” for stairs is that the sum of the riser height and tread depth should equal approximately 17 to 18 inches.

What is the 25-rule for stairs?

The “25-rule” for stairs refers to the recommended relationship between the riser height and the tread depth. The sum of the two should be around 25 inches for a comfortable and safe stair design.

How long can stair stringers be without support?

Stair stringers can generally span a distance of up to 36 inches without requiring additional support. However, this may vary based on the type of lumber used and local building codes.

What is the most comfortable riser height?

A riser height between 7 and 7.75 inches is generally considered the most comfortable for most people.

Is 9 inches too high for a step?

A 9-inch riser height may be too high for some people, as it exceeds the typical comfortable range of 7 to 7.75 inches.

How high should stair riser be for the elderly?

For the elderly or individuals with mobility issues, a stair riser height at the lower end of the comfortable range, around 7 inches, is generally more manageable.

What is the maximum span for a 2×12 stringer?

The maximum span for a 2×12 stair stringer will depend on the lumber grade and local building codes. As a general guideline, a 2×12 stringer may span up to 6 feet without additional support.

What is the max distance between stair stringers?

The maximum distance between stair stringers is typically around 16 inches on center, but it can vary based on local building codes and the stair design.

What is the max distance between deck stair stringers?

The maximum distance between deck stair stringers is usually around 16 inches on center, but it’s essential to check local building codes and structural requirements for your specific deck design.

How far apart should joists be for deck stairs?

The spacing between joists for deck stairs may vary based on the type of lumber used and the design of your deck. As a general guideline, joists are often spaced at 16 inches on center for deck stairs.

Do stringers count in stair width?

Yes, stair stringers are an essential part of the stair width, as they provide the framework for the steps.

Is there an app for calculating stair stringers?

Yes, there are several mobile apps and online tools available that can help you calculate stair stringers and provide stair design recommendations.

How wide should outdoor steps be?

Outdoor steps are typically designed with a width between 36 and 48 inches, allowing for comfortable and safe passage.

What are the two formulas for calculating stair design?

The two common formulas for calculating stair design are the “7-11” formula (7-inch riser height and 11-inch tread depth) and the “golden rule” formula, where the sum of the riser height and tread depth is approximately 17 to 18 inches.

What is the most comfortable stair width?

The most comfortable stair width for most people is around 36 inches, providing ample space for safe and easy movement.

Are stair stringers always at 45 degrees?

Stair stringers are often cut at a 45-degree angle to provide structural support and stability for the stairs.

How do you calculate rise and run of stairs?

To calculate the rise and run of stairs, measure the total height from the finished floor to the upper level, and determine the desired riser height and tread depth based on local building codes and comfort standards.

How do you attach stair stringers without brackets?

Stair stringers can be attached to the deck frame using a variety of methods, including using strong construction adhesive and securing with screws from the sides.

Do you need a footing at the bottom of deck stairs?

Yes, a footing or support system is necessary at the bottom of deck stairs to prevent settling and provide stability.

Do you put the riser or tread on deck stairs first?

It is generally recommended to install the risers first, followed by the treads, when building deck stairs.

Should deck stairs be open or closed?

Deck stairs can be either open or closed, depending on design preferences and local building codes. Open riser stairs may be preferable for outdoor decks to allow water to drain through.

What do you put under stair stringers?

To protect stair stringers from moisture and potential rot, it’s common to place a piece of pressure-treated lumber or a plastic riser material under the stringers.

How do I anchor my deck stairs to the ground?

To anchor deck stairs to the ground, use either concrete footings with post anchors or ground anchors designed for deck construction.

How do I keep my deck stairs from rotting?

To prevent deck stairs from rotting, use pressure-treated lumber for all structural components and keep the stairs well-maintained, including sealing, staining, and regular inspections for any signs of decay.

What is the standard rise and run for deck stairs?

The standard rise for deck stairs is usually around 7 to 7.75 inches, and the run (tread) is typically 10 to 11 inches. These dimensions may vary based on local building codes and individual design preferences.

What do you put under deck stairs?

Under deck stairs, you can place a layer of landscaping fabric or crushed stone to improve drainage and prevent weed growth.

Do deck stairs need rails on both sides?

Deck stairs typically require handrails on at least one side if they exceed a certain height, which varies based on local building codes.

Do deck stairs need handrails on both sides?

Deck stairs usually require handrails on at least one side if they exceed a specific height, but handrails on both sides may be needed based on local building codes.

How many steps before you need a railing?

The requirement for a railing on deck stairs is typically triggered by a stair height threshold, which may vary based on local building codes. Common thresholds are around 30 inches.

What is the maximum steps without a landing?

In general, deck stairs may have a maximum of three steps before requiring a landing. However, this may vary based on local building codes.

Should steps be odd or even?

The number of steps in a staircase is typically odd, as it allows for a balanced centerline and ensures the top and bottom steps align properly.

Can the bottom step be a different height?

The bottom step should have the same height as the other steps in the staircase for safety and to avoid tripping hazards.

Are deck posts supposed to be in concrete?

Deck posts can be placed in concrete footings or secured using other approved methods that meet local building codes.

Should deck posts be buried?

Deck posts are commonly buried in concrete footings or anchored to the ground using other suitable methods to provide stable support for the deck structure.

How many footings do I need for a 12×16 deck?

The number of footings needed for a 12×16 deck will depend on the specific design and local building codes. Generally, a deck of this size may require around 6 to 8 footings.

Is an 8-inch step too high?

An 8-inch step may be considered too high for some people, as it exceeds the comfortable rise range of 7 to 7.75 inches. Steps that are too high may cause discomfort and difficulty while using the stairs.

What is the 27-rule for stairs?

The “27-rule” for stairs suggests that the sum of two times the riser height and the tread depth should be approximately 27 inches for a comfortable stair design.

What is the standard step size and height?

The standard stair step size is typically around 7 inches for the riser height and 10 inches for the tread depth. However, these dimensions can vary based on local building codes and design preferences.

What are the guidelines for stairs?

Stair design guidelines include ensuring comfortable riser height and tread depth, providing secure handrails for safety, and adhering to local building codes and regulations.

How high should a step be from the house to the deck?

The height of the step from the house to the deck should be consistent with the riser height of the deck stairs, typically between 7 and 7.75 inches.

How many steps are in a 4-foot-high deck?

To calculate the number of steps for a 4-foot-high deck, divide the total height (48 inches) by the desired riser height (e.g., 7 inches). The result will give you the approximate number of steps required.

What is the 25-rule for stairs?

The “25-rule” for stairs suggests that the sum of the riser height and the tread depth should be around 25 inches for a comfortable stair design.

What are the three functional requirements of stairs?

The three functional requirements of stairs are safety, ease of use, and compliance with building codes and regulations. Stairs should be designed to prevent accidents and facilitate safe movement between levels.