Coil Length Calculator
How do you find the length of a coil? A Coil Length Calculator helps determine the length of wire needed for a coil based on the outer diameter and the wire diameter. Enter the outer diameter (OD) and wire diameter (WD) into the calculator to find the coil length (CL).
What is Coil Length?
Coil length is the length of wire used to form one complete turn of a coil. This is crucial for designing and manufacturing coils in electrical and mechanical applications.
How to Use the Coil Length Calculator
Using the Coil Length Calculator is straightforward. Here’s how you can do it:
 Enter the Outer Diameter (OD): This is the total diameter of the coil.
 Enter the Wire Diameter (WD): This is the thickness of the wire used to make the coil.
 Find the Coil Length (CL): The calculator will compute the length of wire per coil.
Example Input Values
 Outer Diameter (OD): 10 inches
 Wire Diameter (WD): 0.5 inches
Formula used
The formula to calculate the coil length is:
$CL = (OD – WD) \times \pi$
Variables
Variable  Description 

CL  Coil Length (length per coil) 
OD  Outer Diameter 
WD  Wire Diameter 
How to Calculate Coil Length
1. Identify the Variables:

 OD: Outer Diameter
 WD: Wire Diameter
 CL: Coil Length
2. Plug in the Values:

 OD = 10 inches
 WD = 0.5 inches
3. Calculate:
Subtract the wire diameter from the outer diameter:
$10 – 0.5 = 9.5$
Multiply by π (Pi):
$9.5 \times 3.14 = 29.83$
So, the coil length (CL) is 29.83 inches.
Calculation Examples
Example  Basic Calculation  Advanced Calculation 

Input Values  OD = 10, WD = 0.5  Total Length of Wire = 100, WD = 0.5 
Calculation  CL = (10 – 0.5) × π  Single Coil Length = 0.5 × π × 2 = 3.14 
Result  CL = 29.83 inches  Number of Coils = 100 / 3.14 = 31.85 coils 
Importance and Benefits
Importance  Benefits 

Helps design efficient coils  Accurate wire length calculations 
Essential for electrical engineering projects  Reduces material wastage 
Crucial for manufacturing specifications  Saves time in manual calculations 
Ensures proper coil functionality  Enhances coil performance 
Supports quality control in production  Improves product reliability 
Coil Size Chart
Coil Size  Outer Diameter (OD)  Wire Diameter (WD)  Coil Length (CL) 

Small  5 inches  0.2 inches  15.71 inches 
Medium  10 inches  0.5 inches  29.83 inches 
Large  15 inches  1 inch  43.98 inches 
FAQs
Q1: What if I don’t know the wire diameter?
The calculator needs both the outer diameter and wire diameter to calculate the coil length. You can measure the wire diameter with a caliper or check the information provided by the wire manufacturer.
Q2: Can I use this calculator for noncircular coils?
No, it is suitable only for circular coils because other formulas apply.
Q3: How accurate is the Coil Length Calculator?
The calculator is very precise if the input values are measured correctly. It uses the standard mathematical formula for coil length calculation.
Final Words
I hope you found this tool helpful and easy to use. Your feedback is valuable to us. Please share your experience and let us know if the tool met your expectations.