Who is behind this site
I am Deep Sonic Echo. That is my pen name, the one I use for my music, my writing and everything on this site. In everyday life I am a seafarer from the North: I have spent years at sea, and I write songs and stories in the long hours between watches.
This is not a company or a content farm. It is one person's work: I write the songs, the book and the essays, I choose which calculators to build, and I check the formulas. When something is wrong, it is my mistake to fix, and I want to hear about it.
The song and the book
The song came first. The Most Important Investment arrived as a line, and the book followed it. Anima — The Most Important Investment is a nautical allegory about patience, conviction and investment, told aboard the ship Anima. Every chapter opens with a line from the song.
You can walk the ship on this site: each room keeps its own instrument and the calculators that belong to it. The second song and book, Viaticum — Return on Every Investment, are being written now.
Why a seafarer builds calculators
Life at sea teaches you that you cannot control the weather, only your preparation. You keep a margin of safety, you trust your instruments more than your mood, and you accept that some voyages are long. The same ideas sit at the heart of value investing as Benjamin Graham and Warren Buffett described it, and they run through the book.
When I started doing my own valuation sums, most online calculators were slow, cluttered, asked for an email address or hid the formula. So I built the ones I wanted to use: the Graham Number, discounted cash flow, margin of safety and compound interest, and then the everyday tools people need most, from mortgages to calories.
How the calculators are built
Accuracy. Each calculator uses the standard published formula: amortization for loans and mortgages, the Mifflin-St Jeor equation for calorie needs, the WHO thresholds for BMI, Graham's own formula for the Graham Number and a two-stage discounted cash flow model for intrinsic value. Every page explains its formula so you can check it.
Transparency. A good instrument tells you what it cannot do. Each page lists the main limitations, because a number without its limits gives false confidence.
Privacy. Every calculation runs in your own browser. There is no server, no database and no account, so the numbers you type have nowhere to go except your screen.
Checking. Each calculator is tested against worked examples from textbooks, banks and official sources, on desktop and on mobile. If a result looks wrong, write to me with the page address and the numbers you entered. Calculation errors are always fixed first.
What this site is not
I am not a licensed financial adviser, and nothing here is a recommendation to buy or sell anything. The calculators and essays help you understand the numbers before you talk to a bank, a doctor or an adviser. Read the full disclaimer.
How the site is funded
Everything here is free. When you buy Anima through a link on this site, Amazon pays me a small commission at no extra cost to you. The site carries no advertising today; if that changes, the privacy policy will say so first. I do not sell sponsored posts or paid links.
Contact
Questions, error reports and ideas are welcome at contact@deepsonicecho.com. You can also find me on YouTube, Instagram and Goodreads.