Nichrome Wire Calculator

Heating Resistance Wire Design Tool

Input Fields

Wire diameter

d

mm

Diameter of the nichrome wire

Wire length

L

m

Length of the wire in meters

Voltage

V

V

Applied voltage across the wire

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Calculate automaticallyIf enabled, the result will update automatically when you change any value.

Your Results

Wire Resistance

Current

Power

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Nichrome Wire Resistance and Power Formulas

$$R = \rho \cdot \frac{L}{A}$$ $$A = \pi \cdot \left( \frac{d}{2} \right)^2$$ $$P = \frac{V^2}{R}, \quad I = \frac{V}{R}$$

Where:

• $$R$$ = resistance (Ω)
• $$ρ$$ = resistivity of nichrome ≈ 1.10 × 10^{-6} Ω·m
• $$L$$ = wire length (m)
• $$A$$ = cross-sectional area (m²)
• $$d$$ = wire diameter (m)
• $$V$$ = voltage (V)
• $$P$$ = power (W)
• $$I$$ = current (A)

These equations determine how much resistance, current, and heat the nichrome wire will produce under a specific voltage.

Nichrome Wire – Calculation Example

Given:

• $$L$$ = 1.5 m
• $$d$$ = 0.5 mm = 0.0005 m
• $$V$$ = 12 V

Calculation:

1. $$A = \pi \cdot \left( \frac{0.0005}{2} \right)^2 = \pi \cdot (0.00025)^2 ≈ 1.96 \cdot 10^{-7}~m^2$$
2. $$R = 1.10 \cdot 10^{-6} \cdot \frac{1.5}{1.96 \cdot 10^{-7}} ≈ 8.42~\Omega$$
3. $$I = \frac{12}{8.42} ≈ 1.425~A$$
4. $$P = \frac{12^2}{8.42} ≈ 17.1~W$$

Nichrome wire is commonly used in heating elements due to its high resistivity and heat tolerance. This calculator helps designers estimate resistance and thermal output for various wire sizes and voltages. It supports experimental heating coils, industrial heating applications, foam cutters, and even small DIY kilns. You can use it to size wire for optimal power dissipation and prevent overheating or insufficient heating.