Insertion loss calculator

Input contract, response fields, units, and error behaviour

Both magnitudes must use the same physical unit — watts with watts, milliwatts with milliwatts — because the ratio is unitless only when the units match; the calculator does not convert SI prefixes for you. Numeric values and numeric strings are both accepted so form widgets and spreadsheet paste stay convenient. Classic classroom checks include one watt in and half a watt out for about three point zero one zero decibels of loss, one hundred milliwatts in and ten milliwatts out for exactly ten decibels, and equal powers for zero decibels. POST a JSON body with two required finite positive numbers: p_in, the input or incident power, and p_out, the output or transmitted power. Input power is also accepted under the aliases pin, input_power, Pin, or P_in, and output power under pout, output_power, Pout, or P_out, but only one key may appear for each side of the device. Power must be strictly greater than zero on both ports because IL_dB equals ten log ten of P_in over P_out is undefined for non-positive arguments; zero and negative power fail with invalid_input and a message that zero or negative power is not allowed. Missing fields, conflicting aliases, NaN, and Infinity fail the same way and are not charged. On success the response includes cleaned p_in and p_out, power_ratio as P_in over P_out, transmission_ratio as P_out over P_in, insertion_loss_db as the decibel result, kind as loss, gain, or unity, booleans is_loss, is_gain, and is_unity, a short expression string showing the formula with numbers, method insertion_loss, and the formula string IL_dB equals ten log ten of P_in over P_out. Pricing for successful API calls is the published base of $0.002 per item; validation failures do not consume prepaid balance.

Where insertion-loss calculations show up in real work

Introductory RF and microwave labs constantly assign filter, cable, and attenuator drills so students can move between linear power ratios and datasheet insertion-loss figures without mixing the ten-log and twenty-log formulas. Component vendors quote insertion loss versus frequency on every filter, connector, and coaxial jumper; converting two bench power-meter readings into that figure keeps incoming inspection honest. Transmitter and receiver teams budget cascade loss by adding each stage's insertion loss in decibels instead of multiplying awkward linear fractions that hide a factor-of-two error. Optical and microwave metrology reports often mix milliwatts and dB of loss on the same page, so a single trusted closed form prevents sign errors when someone confuses insertion loss with power gain, which is the negative of the same logarithm. Because this capability is a pure parse engine, API pricing is the published base of $0.002 per successful item and failed validation does not consume balance. The browser tool is free for interactive use; scripted API traffic uses prepaid KIT balance at the published rate without hidden per-field surcharges.