Numerandi

Small tools that do one job well

About Numerandi

Last reviewed: September 24, 2026

Numerandi publishes small, browser-based calculators for freelance and self-employed finance decisions. Each tool answers one job, shows its working, and labels the tax year and sources it uses. The site is operated by Chris Mitchell. The calculators are informational tools, not tax or legal advice.

Who runs Numerandi?

Chris Mitchell runs Numerandi as the publisher of numerandi.com. There is no separate company office, phone line, or staffed help desk. Questions about the site go to[email protected] on theContact page.

The footer on every page names that publisher: © Numerandi / Chris Mitchell. Privacy and terms use the same identity so a reader can tell who is responsible for the site.

What is this site for?

Freelancers and other self-employed people often need a first number before they talk to a tax professional or send a quote. Numerandi is for that first number: self-employment tax, quarterly estimates, a sustainable hourly floor, 1099 versus W-2 take-home, and related cash and pricing questions.

The site is not a filing service, bookkeeping product, or advice practice. It does not open accounts, store the numbers you type, or file anything with the IRS. Calculations run in your browser. Browse the full set on All tools, or start from thetaxes, rates and pricing, andcash flow hubs.

Where does the name come from?

Numerandi comes from ars numerandi, Latin for “the art of counting” and the title of a 15th-century arithmetic treatise. On this site that means a calm, inspectable answer with the formula left visible. The homepage states the same origin so the name is not a black box.

How are the tools maintained?

Tax-year figures, wage bases, deduction limits, and due dates live in a rates registry. Each calculator page labels the tax year it uses and the date those figures were last checked against the cited IRS, SSA, or other primary source. When a page cites a source, the citation is a direct link, not a paraphrase of an unsourced number.

The tools have limits on purpose. A calculator models the job on the page and states what it leaves out: state tax, credits, filing status details, or a full return. If the math and the explanation disagree, the page is treated as unfinished. Results depend on the values you enter and the assumptions written next to them.

Maintenance does not mean the result is your tax. Rates change midyear. A later form or notice can change what you owe. Verify an important number against current IRS instructions or with a qualified professional before you file or pay.

Which tools should you start with?

Use the tool that matches the decision in front of you. These are the usual starting points:

Every published calculator is on All tools. Related articles sit on the same hubs and point back to the one calculator that owns the math.

Are these results tax or legal advice?

No. Numerandi provides general information. A result is not a filing position, a legal conclusion, or a recommendation to take a job, elect an entity, or send a payment. Your complete facts, state rules, and current IRS guidance control.

Tax and legal disclaimer: These pages and calculators are informational only. They are not tax, legal, or financial advice. Numerandi / Chris Mitchell does not prepare returns or represent you before the IRS. Confirm important results independently, or with a qualified professional, before you file, pay, or sign a contract.

How can you reach Numerandi?

Use Contact for questions about the site. ReadPrivacy for how calculator entries stay on your device and how advertising is disclosed. Read Terms for the conditions of use. Those three pages, this About page, and All tools are the public record of who runs Numerandi and what the site is for.