About Reverb Calculator

Why this site exists

We kept watching the same small problem repeat in session after session. A producer would find a tempo table in a forum post, a screenshot, or an old notebook, copy one row that happened to match the song, and then re-derive the whole table by hand the moment the tempo changed. The math itself takes seconds. Finding a trustworthy version of it, in the middle of a mix, never did.

So we published the table properly. The combined reverb and delay calculator on the home page puts reverb pre-delay, decay and delay times on one screen, at any tempo, and the Methodology page shows exactly how each value is derived. Every other tool here — the Delay Calculator, the Pre-Delay Calculator, the type and vocal pages — is the same idea cut for one job, so nobody has to rebuild the arithmetic mid-session again.

The site stays deliberately small. One intent family, a complete set of tools, no accounts, no downloads, and nothing between you and the numbers. If a value here saves you a notebook page, it has done its job.

About Ian Welkins

I am Ian Welkins, and I am based in Houston, Texas. I build small, single-purpose calculators for the web — one clear job per site, done thoroughly, with the method published alongside the answer. Reverb Calculator is one of mine, and I maintain it myself.

I also mix music as a hobbyist, which is where this site came from. For years I kept a notebook table of pre-delay and decay values worked out at 120 BPM, because that was the tempo of the first track I ever mixed. It was accurate for exactly one tempo. Every other song meant fresh long division on a notebook page, usually while a vocal take was waiting. Eventually the notebook became this tool: pick a tempo, and the values I used to derive by hand are simply there, for every room size and note value.

You can find me elsewhere on GitHub, where the code side of my projects lives, on Dev.to, where I write occasionally, on About.me, and on Gravatar, which carries the photo used across my author pages. My full author page on this site is Ian Welkins.

How the tools are built

Every formula on this site comes from published sources — standard tempo arithmetic for the delay and reverb timing tools, and the Sabine and Eyring formulas for the RT60 Calculator — and the sources are named on the pages that use them. There is one shared calculation library behind all the tools, so the BPM to MS Chart and the console on the home page can never quietly disagree with each other.

Everything is computed locally in your browser. There are no accounts, no server round-trips for a calculation, and nothing to install. You set a BPM, the page does the division, and the table updates instantly. Before a tool ships, its output is checked against worked examples computed by hand, including edge cases at the slowest and fastest tempos the tools accept.

A note on AI

We want to be plain about this: AI tools help with drafting text and writing code on this site, the way a spellchecker or a sample library helps in a studio. They are assistance, not authorship of the numbers.

Every formula, preset and value here is checked by hand against the published sources before it ships, and the worked examples on the Methodology page are reproduced by hand so a reader can verify them too. When a number is wrong, that is a human maintenance failure, and it gets fixed openly — see the Editorial Policy for how corrections work, or report an error if you spot one.

Above all: this site is maintained by a person who answers email. If you write in, you are writing to Ian, not to a model and not to a team inbox.

Frequently asked questions