Codename Chalmers

For years my retirement planning has lived in a spreadsheet — a big, ugly, opinionated one that I trust more than any of the tools on the market. Chalmers is that spreadsheet, rebuilt as a web app.

What it is

Chalmers is a retirement planning tool. You tell it about your situation — your super or retirement savings, your contributions, your expected spending — and it projects what you’ll have, what you can safely withdraw, and how long it’s likely to last.

The numbers update daily from live market data (via an API or scraper, exact source tbc), so the projection you look at this morning isn’t stale by the weekend.

There are two ways into it:

• Simple: answer a handful of questions and get a plain-language projection. No jargon, no hidden assumptions.
• Advanced: the full spreadsheet, exposed. Every assumption is on the table and adjustable — because a retirement tool you can’t interrogate isn’t a tool, it’s a black box.

Country by country

Tax is the silent drag on retirement savings, and its treatment differs enormously between countries — contribution caps, earnings taxes, withdrawal rates, pension offsets. Chalmers estimates tax drag country by country rather than pretending one set of rules applies everywhere.

It starts with Australia, then New Zealand, Canada, the US, and the UK.

Privacy and security

Chalmers is completely anonymous. There are no accounts, no emails, no names — nothing that connects a projection to a person. I don’t want to know your information, and the tool shouldn’t either.

But the inputs are still the sort of data you’d rather not leak, so security is always front of mind: everything runs over HTTPS, projections are computed locally where possible, and nothing is stored unless it absolutely has to be.

The disclaimers

The big ones. Chalmers is a model, and every model is wrong — markets are uncertain, tax rules change, and life happens. We try our best, but you should really talk to a financial advisor or a qualified accountant before making any decisions based on what you see here. This is a tool for thinking, not advice.