Welding Calculator

Find a fillet weld's effective throat and cross-sectional area.

How the Math Works

The welding calculator uses two fundamental formulas to determine fillet weld characteristics. The throat thickness is calculated by multiplying the leg length by 0.707, which is derived from the geometric relationship in an isosceles right triangle where the throat represents the shortest distance from the root to the face. The weld area is found using the formula 0.5 times leg squared, representing the area of a right triangle formed by the two equal legs of the fillet weld.

Practical Applications

To use this calculator practically, first measure the leg length of your fillet weld - this is the distance from the root to the end of the weld along both the horizontal and vertical surfaces. Multiply this measurement by 0.707 to determine the effective throat thickness, which is critical for structural calculations. Then calculate the weld area by multiplying 0.5 by the square of the leg length to determine material requirements and load-bearing capacity.

Day-to-Day Use

This calculator helps ensure your welding projects are both safe and efficient in everyday applications. Whether you're building furniture, repairing equipment, or constructing DIY projects, knowing the exact throat and area of your welds prevents over- or under-welding, saving both time and materials. It also helps you verify that your welds meet required strength specifications for automotive repairs, fence construction, or artistic metalwork without needing complex engineering calculations.

Worked example

6 mm leg → throat 4.24 mm, area 18 mm².

FAQ