I've been building a UK-specific retirement planning calculator called FIRElogic and I'm looking for a small group of beta testers from the FIRE community before a wider release.
The reason it exists: most of the well-known planning tools are US-built and don't handle UK specifics properly — SIPP drawdown rules, the 25% PCLS, ISA vs GIA tax treatment, the personal allowance taper at £100k, State Pension timing, IHT with the RNRB taper, and so on. I wanted something that modelled all of that natively rather than approximating around it.
What it does at the moment:
- Multi-person households with different retirement ages
- SIPP, ISA, GIA, DB pensions, annuities, rental income, NS&I Premium Bonds as first-class assets
- Drawdown ordering with optional SIPP band-filling (draw to the basic-rate ceiling, recycle into ISA)
- Annual review mode so you can track actual vs projected over time
- API-driven stress testing
- IHT projection including RNRB taper
What I'd want from beta testers: run your own numbers through it, tell me where the assumptions don't match your situation, flag anything that produces results that look wrong, and generally be honest about what's confusing or missing. Probably 2-3 hours total over a few weeks, no obligation to keep using it.
In return: free access through the beta and beyond, direct line to me on bugs and feature requests, and your input shapes what gets built next.
If you're interested, drop a comment or DM with a sentence or two on your situation (rough age, FIRE timeline, asset mix) so I can get a reasonable spread of test cases. Looking for maybe 15-20 people to start.
Happy to answer questions about the methodology, the underlying calculation engine, or anything else in the comments.