Business Calculators

Six calculators for the questions that come up when a decision needs a number behind it. Each one shows the formula, works the whole solution out step by step on the figures you enter, and links to the federal datasets the inputs should come from.

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Market size (TAM/SAM/SOM)Build a market size bottom-up from a countable account universe, narrow it with the constraints that actually apply, and test the share target against what your sales team can physically close.Survey sample sizeHow many responses a survey needs for a given confidence level and margin of error, using Cochran's formula with the finite-population correction.Margin of errorThe precision a survey result actually carries: the confidence interval around a proportion for a given sample size.A/B test significanceWhether the difference between two conversion rates is larger than chance, by two-proportion z-test, with the confidence interval on the difference.CAGR (compound growth)The compound annual growth rate between two values, plus doubling time and a forward projection at the same rate.Inflation adjustmentRestate an amount in another period’s dollars using CPI index values you take from the live BLS series — no embedded price table to go stale.

Verified data tables

Alongside the calculators: sector-by-sector tables of public-company financials where every row links to the exact SEC filing it came from. Sort them, download the CSV, or embed one on your own site — free with attribution.

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What these do differently

Most calculators hand back a number and stop. These show the arithmetic: the formula in symbols, then the same formula with your own figures substituted into it, line by line, down to the answer. You can reproduce the result by hand, check it, and defend it to whoever asks where it came from.

They also say when not to trust them. Where a method has a boundary — a sample too small for the normal approximation, a market share assumption that would be extraordinary if achieved, a growth rate computed from a base so small the percentage stops meaning anything — the page says so next to the answer instead of printing a confident figure and leaving you to find out later.

And they hold no data of their own. Where a calculation needs a published figure — CPI index values, an addressable account count — the page asks you for it and links to the agency that maintains it, rather than embedding a copy that begins going out of date the day it ships.

Everything runs in your browser. Nothing you type is transmitted, stored, or logged.

This page does the arithmetic. We check the numbers you put into it.

These tools do the arithmetic on numbers you already have. A $29 Verified Snapshot answers one business question in a short, fully cited brief — and every claim in it is checked against its own source before it ships. Others check that links work. We check that claims are true.

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These calculators are provided for general business analysis and are independent informational research — not investment, financial, legal, or tax advice. The arithmetic is standard and openly documented on this page; the assumptions you enter are yours, and the conclusions drawn from them are too.