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Rafter Length Calculator

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Welcome, The Rafter Length Calculator will assists you in determining the correct length of your rafters. For the Basic Calculator, simply enter the rafter run (in feet) and the angle of the rafter (in degrees) to find the rafter length.

For a more detailed calculation, use the Advanced Calculator. Enter the total run, total rise, and pitch to get the total rafter length. Select the calculator that meets your needs, fill in the necessary fields, and obtain accurate rafter length measurements for your construction projects.

Length of Rafter Calculator

Enter two values to calculate the third










Enter the run, rise, and pitch to calculate the total rafter length.













Want to know how to calculate rafter length easily? You’re in the right place. With the right calculator, you can get accurate measurements without the headache. I’ll show you how it works and why it’s important.

How to Calculate Rafter Length: A Comprehensive Guide for DIY Enthusiasts

Calculating rafter length might sound tricky, but it’s not. The rafter runs from the roof’s peak to its edge. The length depends on the roof’s pitch and the span (distance between walls).

Term Definition
Roof Pitch The slope or angle of the roof
Span The distance between two support walls

For example, if your roof pitch is steep, the rafter will be longer than for a flat roof with the same span.

Simplify Roof Construction for Homeowners

Using a rafter length calculator saves time and prevents errors. Just input the span and pitch, and the calculator gives you the length instantly.

Input Function
Roof Pitch Measures the angle of the roof’s slope
Span The width between walls supporting the roof

For example, if you enter a roof pitch of 6/12 and a span of 14 feet, you’ll get an accurate rafter length in seconds.

Common Rafter Length Charts and Calculations Explained

If you don’t have a calculator handy, rafter charts can help. These charts list roof pitches and spans, showing you the correct rafter length for each combination.

Pitch Span (ft) Rafter Length (ft)
4/12 12 13.42
6/12 16 18.86

For example, if your roof is 6/12 pitch and 16 feet wide, the chart tells you the rafter length is 18.86 feet.

Step-by-Step Guide to Calculating Rafter Size with Overhang

If your roof has an overhang, you’ll need to add that to the rafter length. Here’s how you calculate it step by step.

Step Action
Step 1: Measure span Measure the distance between the walls
Step 2: Find roof pitch Use a calculator or measurement tool
Step 3: Add overhang Add the overhang length to your result

For example, if your calculated rafter length is 14 feet and you have a 2-foot overhang, your total rafter length is 16 feet.

Calculate 12 Pitch Rafter Length Easily

Roof pitch is a key factor in rafter length. It’s usually expressed as rise over run. A 12/12 pitch means your roof rises 12 inches for every 12 inches of horizontal distance.

Pitch Meaning
12/12 Pitch Steep roof, where the rise equals the run
6/12 Pitch Moderate slope, where the rise is half the run

For a 12/12 roof, just plug the span into the calculator, and it gives you the rafter length.

Roof Rafter Size Charts: Essential for Accurate Roof Framing

Size charts are incredibly useful when framing a roof. They tell you the rafter length based on the roof pitch and span.

Pitch Span (ft) Rafter Length (ft)
4/12 14 15.49
8/12 16 17.89

These charts help you get the right measurements, especially if you’re working with a contractor.

Calculating Rafter Angles Made Simple: A DIY Guide

Rafter angles might seem hard, but they’re easy with a formula. The angle comes from the roof’s pitch. Use this formula:
Angle = tan⁻¹(pitch/12)

Pitch Rafter Angle
4/12 Pitch 18.43°
6/12 Pitch 26.57°

For example, a 6/12 pitch gives you an angle of about 26.57°.

4/12 Roof Pitch Calculator: Perfect for Your Roofing Project

A 4/12 pitch is common for many homes. It’s not too steep, making it easier to work on. Use our calculator to find the rafter length for this pitch.

Pitch Span (ft) Rafter Length (ft)
4/12 12 13.42
4/12 16 17.89

Just enter the numbers, and the calculator gives you the rafter length.

How to Calculate Rafter Length from Roof Pitch: A Beginner’s Guide

New to roof framing? No problem. Calculating rafter length from roof pitch is simple. You need two things: the pitch and the span.

Step What to Do
Step 1: Find the pitch Use a pitch finder or calculator
Step 2: Measure the span Get the distance between the two walls
Step 3: Input values Enter data into the rafter calculator

For example, with a 6/12 pitch and a 14-foot span, you’ll get a rafter length of about 15.62 feet.

Geometry in Roofing: Calculate Rafter Length with Ease

Roofing involves simple geometry. The rafter forms a right triangle with the rise and run. Use the Pythagorean theorem to calculate rafter length:
Rafter Length² = Span² + Rise²

Span Rise Rafter Length
12 feet 6 feet 13.42 feet
16 feet 8 feet 17.89 feet

This formula ensures you get the right rafter size every time.

Choosing the Right Rafter Size for a 12 ft Rafter: A Detailed Guide

If your rafter length is 12 feet, you’ll need the right size for strength. Larger spans need thicker rafters to support the roof.

Rafter Length Material Recommended Size
12 feet Wood 2×6 or 2×8
14 feet Wood 2×8 or 2×10

Always check your local building codes to make sure your rafters meet safety standards.

With this guide and our rafter length calculator, you’re all set to tackle your roofing project. Whether you’re building a shed or fixing up your home, these tools will help you get perfect rafter measurements every time.

 
 
 
 
 

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