About The Drill Down

The Drill Down exists because too many SaaS metrics get computed wrong, cited wrong, and then repeated wrong. This is the reference I wanted when I was the person in the room being asked what the number actually was.

Why this site exists

Search for "LTV calculator" and you will find a dozen widgets that take three inputs, divide two of them, and hand back a number with no working shown and no warning about the traps. Half of them compare a revenue-based LTV against a cash-based CAC, which is not a like-for-like comparison and quietly overstates the answer. None of them tell you what happens when churn is zero.

The Drill Down does the opposite. Every calculator shows the formula with your figures substituted in, flags the traps, and links to a definition and a benchmark so the number means something. If a calculation would divide by zero, it refuses to print a fiction and tells you why. The goal is for an operator, a founder, or an analyst to be able to check our maths in ten seconds and then cite us with confidence.

Tom Askey, founder

I spent several years in FP&A (financial planning and analysis) at two B2B SaaS companies as they scaled from a few million in ARR upward. My job was building the metrics packs that boards actually read: retention cohorts, CAC payback by channel, the Rule of 40 walk, the burn multiple nobody wanted to look at. I watched the same handful of definitional mistakes cost real decisions, and I got tired of re-explaining why NRR and NDR are the same thing and why gross margin belongs inside LTV.

The calculators here are the formulas I used, published, with the assumptions written down. The benchmark ranges are the guide rails I judged our own numbers against, framed honestly as ranges rather than false precision.

How the calculators are checked

• Every formula is stated openly on its calculator page, so it can be audited rather than trusted.
• Edge cases are handled deliberately: zero churn, zero CAC, and negative net burn each return an explained result instead of a misleading number.
• Definitions across the site are internally consistent and match the glossary, so figures line up between tools.
• Nothing here runs on a server or stores your inputs: the maths happens in your browser and your numbers never leave it.

How the site is funded

The Drill Down is free and currently carries no ads and no affiliate links. If that changes, it will be disclosed plainly on this page, and it will never change what a formula returns. The calculators exist to be useful and to be cited; that is the whole business model for now.

Contact

Spotted a formula you would compute differently, or a benchmark that has moved? That is exactly the mail I want: hello@thedrilldown.co.uk. Corrections get published, not buried.