Practical engineering utilities

RF, audio and streaming calculations without the clutter.

Fast, transparent calculators for amateur radio operators, audio engineers and internet-radio operators. Every result shows the assumptions and the underlying formula.

Open Frequency ↔ Wavelength Browse all tools

Live toolbox 12 calculators

Execution Browser-based

Method Transparent formulas

Toolbox at a glance Live

RF 7 calculators

Wavelength, antenna length, power, ERP/EIRP, SWR, FSPL and full link budget.

Audio 2 calculators

PCM file size and practical audio-level conversion for engineering bench work.

Streaming 3 calculators

Bandwidth, listener capacity, transfer and archive storage requirements.

RF bench work Amateur radio Audio engineering Internet radio

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Toolbox

Built around real engineering questions.

Frequency ↔ Wavelength

Convert frequency to free-space wavelength, or wavelength back to frequency.

Live RF

Antenna Length

Dipoles, quarter-wave verticals and loops, with live drawings, loop-shape selection and matching guidance and practical matching diagrams.

Live RF

RF Power Converter

Convert between W, mW, dBW and dBm, with equivalent voltage across 50 Ω, 75 Ω or a custom load.

Live RF

ERP / EIRP

Calculate radiated power from transmitter output, feedline losses and antenna gain in dBi or dBd.

Live RF

SWR / Reflected Power

Calculate SWR, reflected power, delivered power, return loss and reflection coefficient in either direction.

Live RF

Free-Space Path Loss

Calculate FSPL from frequency and distance, or solve backwards for distance from a known path-loss budget.

Live RF

RF Link Budget

Calculate received power and link margin end-to-end, or solve for maximum ideal free-space distance.

Live Audio

Digital Audio File Size

PCM/WAV bitrate, storage and reverse duration from sample rate, bit depth and channels.

Live Audio

Audio Level Converter

Convert dBu, dBV, Vrms, Vpeak and Vpp with clearly stated reference levels.

Live Streaming

Streaming Bandwidth

Outbound bandwidth from stream bitrate, simultaneous listeners, overhead and headroom.

Live Streaming

Maximum Listeners

Estimate listener capacity from available bandwidth, stream bitrate, overhead and reserve.

Live Streaming

Data & Storage

Estimate listener transfer or archive storage per day, month and year.

Live

Transparent

Formula shown

Each calculator explains what it is doing so the result can be independently checked.

Private

Runs locally

Version 1 calculations run entirely in the browser. Input values are not sent to a calculation server.

Practical

Engineering units

Use the units encountered at the bench: MHz, GHz, metres, feet, dBm, dBu and more.