# Physical Properties of Coil Calculator

Determine resistance, total wire length, and number of windings.

Utilize this online electrical calculator to compute the physical characteristics of a coil or material, including resistance, total wire length, and number of windings. The calculator assumes the wire to be copper when calculating resistance and voltage.

Wire Diameter
mm
Number Of Turns
Bobbin Length
mm
Bobbin Diameter
mm
Current
A
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3 Number of calculations

T = \frac{bl}{d}
n = \frac{\text{Turns}}{T}
cd = (2 \cdot n \cdot d) + bd
r = \frac{n \cdot d + bd}{2}
a = \pi \cdot r \cdot r
L = \frac{2 \cdot \pi \cdot r \cdot n}{1000}
\text{rpm} = 0.0333 \cdot \frac{(\frac{0.812}{2})(\frac{0.812}{2})}{(\frac{d}{2})(\frac{d}{2})}
R = \text{rpm} \cdot L
V = R \cdot I
P = V \cdot I

Where,

• T = Turns per winding,
• bl = Length of Bobbin,
• d = Wire Diameter,
• n = Number of windings,
• cd = Outer diameter of the coil,
• bd = Diameter of Bobbin,
• r = radius of the middle of the coil,
• a = Cross-sectional area,
• L = Total Length,
• rpm = Resistance/meter,
• R = Resistance,
• V = Voltage at Rated Current,
• I = Current,
• P = Power at Rated Current,