Accounting · Finance · Business decisions
Do the finance maths, properly.
166 calculators, converters and side-by-side comparisons, a 507-term finance glossary, and self-paced courses — built for accountants, finance professionals and the people running a business.
166
tools
calculators, converters, comparisons and use cases
507
glossary terms
each on its own page, plain English
10
courses
self-paced, text-based, no video
49
resources
templates and guides you can download
What you can do here
Five things, each of them finished.
Calculate
Retirement, tax, loans, business cash flow — with the assumptions shown, not hidden.
Convert
Sales tax by state, margin and markup, unit and rate conversions.
Compare
Two options side by side on your numbers: 401(k) vs Roth, buy vs rent, 15 vs 30 year.
Decide
Whole situations worked end to end — a backdoor Roth, retiring at 50, quarterly tax on 1099 income.
Look it up
Every term on its own page, defined in plain English, linked to the tools that use it.
Start here
The ones people open first.
Compound Interest Calculator
What a balance becomes over time, with contributions.
Capital Gains Tax Calculator
Short- and long-term gains on stocks, crypto and property.
Mortgage Payment Calculator
Monthly payment, total interest and the amortisation curve.
Break-Even Calculator
The units and revenue that cover fixed and variable cost.
15-Year vs 30-Year Mortgage
Which term actually costs less, and what you give up.
Buy vs Rent
Which builds more wealth on your numbers, not a rule of thumb.
Learn and take away
Reading you can work from.
Courses
Text-based and self-paced: financial modelling, stock market analysis, options, futures, risk. One is free and open to everyone.
E-books
In-depth PDF guides on tax, real estate, equity compensation, investing and finance careers, priced per guide.
Templates
Spreadsheets and working documents built to be opened and used, not admired.
The blog
Longer pieces on the questions the tools answer, and the reasoning behind them.
Why this site
Built to be checked.
The assumptions are visible
Every calculator states what it assumes and which rules it applies. A number you cannot interrogate is not an answer.
One decision per page
Tools are scoped to a question — not a dashboard of everything, which is how a tool ends up answering nothing.
Written for practitioners
For people who already know what a basis point is and want the calculation, not the introduction.
Free where it can be
Every tool and every glossary term is free and needs no account. Courses and e-books are paid; nothing else is gated.
Start with the question you actually have.
No account, no email, nothing to dismiss. Open a tool and get the number.
