A current value can be written in amperes, milliamperes, or microamperes, and a circuit design question can ask how much voltage a given current loses along a run of cable. The electric current converter and the cable size calculator sit at different points in the same workflow: one changes the unit label on a current value, and the other consumes a current in amps — together with voltage, run length, and conductor resistance — to estimate voltage drop and a preliminary conductor size. The converter changes the unit only; the cable size worksheet is a planning estimate that defers to adopted codes and qualified electricians.
What each calculator does
The electric current converter converts among amperes, milliamperes, and microamperes through the ampere as base, using factors 1, 0.001, and 0.000001. It multiplies the entered value by the source factor and divides by the target factor, formatting the result to six decimal places. Its worked example converts 37.5 mA to 0.0375 A, with the full list showing 37.500000 mA and 37,500.000000 µA. The page is explicit about what it does not do: it does not model voltage, resistance, waveform shape, duty cycle, conductor heating, or fuse behavior, and it is not a safety check for mains wiring, breakers, or conductor sizing.
The cable size calculator is a preliminary conductor-sizing worksheet. You enter voltage, current, one-way run length, and a candidate-conductor resistance in ohms per 1,000 feet. For a two-conductor path it computes voltage drop as 2 × current × resistance × one-way length ÷ 1,000, and percentage drop divides that result by system voltage — for example, 120 V, 16 A, 50 ft, and 1.93 Ω/1,000 ft gives 3.088 V, or 2.57%. The page states plainly that the worksheet does not choose wire size, determine ampacity, or establish electrical-code compliance; resistance should come from current manufacturer data, and safety-critical sizing belongs to the applicable installation.
Side-by-side
| Electric current converter | Cable size calculator | |
|---|---|---|
| Question | What is this current in another unit? | What voltage drop does this current cause over this run? |
| Inputs | Nonnegative value, From and To unit | Voltage, current, one-way run length, resistance in Ω/1,000 ft |
| Units | Amperes, milliamperes, microamperes | Amps, volts, feet, ohms per 1,000 feet |
| Core math | Value × source factor ÷ target factor (1, 0.001, 0.000001) | Drop = 2 × I × R × L ÷ 1,000; % = drop ÷ V × 100 |
| Example | 37.5 mA = 0.0375 A = 37,500 µA | 120 V, 16 A, 50 ft, 1.93 Ω/1,000 ft → 3.088 V (2.57%) |
| Output | Selected conversion plus all three equivalents | Voltage drop, percentage, and preliminary sizing context |
| Scope | Unit conversion only; not a safety check | Preliminary estimate; not code compliance |
When to use which
Use the electric current converter when you hold a current and need the same current in another scale — a data sheet listing 37.5 mA that belongs in an ampere-based power budget, a microcontroller sleep current in µA, or an LED branch current in mA. The page warns against mixing mA and µA in battery spreadsheets, where a one-prefix error changes the result by 1,000, and against reading a supply’s maximum current rating as the current a load will draw.
Use the cable size calculator when you are estimating a conductor for a specific run: a voltage and a current, a one-way distance in feet, and a resistance figure for the candidate conductor. Use the result as a planning value for preliminary quantity and geometry decisions, and keep input precision consistent with your measurements. The worksheet also points to the stud spacing and square footage calculators for the framing and room dimensions around a load estimate.
The natural chain runs from the converter to the worksheet: relabel a current into amperes first, then feed amps, volts, feet, and conductor resistance into the voltage-drop estimate. Neither tool replaces an electrician or the adopted code — the converter explicitly says so, and the worksheet’s own scope statement says the same.
Limits and disclaimer
The electric current converter accepts only nonnegative magnitudes and does not model the circuit around the current: voltage, polarity, protection, and operating limits are separate questions. The cable size worksheet is jurisdiction- and edition-specific by design; it does not choose wire size, determine ampacity, or establish code compliance, and resistance should be taken from current manufacturer data. Electrical work should be designed and checked for the applicable installation, and neither result here is a substitute for that.