🧵 Wire Gauge & Voltage Drop Calculator

AWG resistance · voltage drop & power loss · current density check · harness mass

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Inputs

Results

Conductor area
– mm²
Loop resistance
– mΩ
Voltage drop
– V
Drop / bus voltage
– %
Power loss
– W
Current density
– A/mm²
Copper mass (incl. insulation)
– g
–
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📖 How to use

  1. Enter current, bus voltage, run length and pick an AWG; use parallel wires for high-current feeders.输入电流、母线电压、走线长度并选 AWG 线规；大电流馈线可用多根并联。
  2. Keep the voltage drop under ~1–2% of the bus for power feeders, and current density under ~5 A/mm² (vacuum derating, bundled).动力馈线压降控制在母线的 1–2% 以内，电流密度不超过约 5 A/mm²（真空降额、成束敷设）。
  3. Use the conductor temperature for hot-case sizing — resistance is ~20% higher at 70 °C than at 20 °C.按热工况设置导体温度——70 °C 时电阻比 20 °C 高约 20%。
  4. The mass figure (×1.35 insulation factor) helps trade gauge vs harness mass across the whole spacecraft.质量结果（含 ×1.35 绝缘系数）可用于全星范围内线规与线缆质量的权衡。

Wire sizing relations

AWG diameter: d = 0.127·92^((36−n)/39) mm; copper resistivity 0.0172 Ω·mm²/m at 20 °C, scaled by 1+0.00393·(T−20).

R = ρ·L_loop/(A·N_par), ΔV = I·R, P_loss = I²·R, mass = A·L·N_par·8.96 g/cm³ ×1.35 for insulation.

Spacecraft derating (e.g. ECSS-Q-ST-30-11) limits bundle currents well below terrestrial ratings because there is no convection in vacuum — the ~5 A/mm² check here is a first-cut screen, not a substitute for the standard.

All computation runs locally in your browser.

导线设计关系式

AWG 直径：d = 0.127·92^((36−n)/39) mm；铜电阻率 20 °C 时 0.0172 Ω·mm²/m，按 1+0.00393·(T−20) 修正。

R = ρ·L_回路/(A·N_并)，ΔV = I·R，P_损 = I²·R，质量 = A·L·N_并·8.96 g/cm³ ×1.35（绝缘）。

航天降额（如 ECSS-Q-ST-30-11）规定的成束载流远低于地面额定值——真空中没有对流散热。本页约 5 A/mm² 的检查是初筛，不能替代标准。

全部计算在你的浏览器本地完成。