Electronics calculator

Type values with prefixes: 4.7k, 2k2, 10m, 100n, 4R7, 1M.

Ohm's law and power

Fill in any two. The other two are calculated.

Voltage (V) Current (A) Resistance (Ω) Power (W)

Enter values separated by commas or spaces.

Component

Values

Vout is measured across R2 (the bottom resistor).

Vin (V) R1 top (Ω) R2 bottom (Ω)

Gives the exact value and the nearest E24 standard resistor.

Vin (V) Target Vout (V) R2 bottom (Ω)

Two resistors in parallel sharing a total current.

Total current (A) R1 (Ω) R2 (Ω)

A capacitor charging through a resistor. Target voltage is optional.

Resistance (Ω) Capacitance (F) Supply (V) Target voltage (V)

Mode R1 (Ω) R2 (Ω) C (F)

Typical Vf: red 2.0 V, yellow 2.1 V, green, blue and white 3.0–3.3 V.

Supply (V) LED forward voltage (V) LED current (A) Number of LEDs LEDs per string

Cells in series add voltage. Cells in parallel add capacity.

Cells in series (S) Cells in parallel (P) Cell capacity (mAh) Cell nominal (V) Cell full (V) Cell empty (V) Max cell current (A)

For devices that sleep, enter the sleep current and the share of time spent active.

Capacity (mAh) Nominal voltage (V) Usable capacity (%) Active current (A) Sleep current (A) Active time (%)

AWG accepts 0–40 and 1/0 to 4/0. Round trip counts the return wire too.

Material Size given as Size Length (m) Path Current (A) Supply (V) Temperature (°C)

Bands

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Uses the band count selected above (4 or 5 bands).

Resistance (Ω)

3-digit (103), 4-digit (1002), R notation (4R7, R10) or EIA-96 (01C).

Code

3-digit code in pF, with optional tolerance letter (104K, 225J, 4n7).

Code