ZBee vs ProjectionLab
Last reviewed: September 2026
ProjectionLab is the closest thing ZBee has to a philosophical cousin: both are built by small, independent teams, both take privacy seriously, and both refuse to become another sell-your-data finance site. The difference is the kind of tool each one is. ProjectionLab is a sandbox — you type in your finances and model any life scenario you can imagine, with some of the best charts in the category. ZBee is an instrument — it connects to your real brokerage accounts and measures one thing: the most you can safely spend.
The one-line version: ProjectionLab is for modeling the lives you might live; ZBee is for measuring the spending your actual accounts support.
| ZBee | ProjectionLab | |
|---|---|---|
| Where your data lives | On your Mac — by design, not policy | Their cloud (the self-hosted edition was discontinued) |
| Platform | Native Mac app | Web |
| Native iPhone app | Free iPhone & iPad app — a private, on-device estimate | No app — web/PWA |
| Uses your real accounts | Yes — read-only, direct to your Mac | No — you type them in |
| What linking brings in | Your actual holdings — every position, priced as of your last sync | No linking |
| Core question | Most you can safely spend | Model any scenario |
| A yearly spending figure with guardrail thresholds |
Yes — this year's trigger points in dollars: the level below which the rules trim (and to what), and where a raise is earned. Published Guyton-Klinger rules you can verify by hand | Modeled inside projections — no live yearly readout |
| Would it have survived real market history? |
Yes — automatically: your safe-spend number is replayed through every real market sequence since 1928 (1929, 1966, 1973 and all) and reported as "survived N of M," with any failing years named | Historical backtest available — you set it up per scenario |
| Year-by-year tax detail (you can audit) |
Yes — federal, state, IRMAA, NIIT, RMDs, shown | Yes |
| Roth-conversion optimizer | No, by design: enter the Roth plan you or your adviser chose and see exactly what it does | Yes, since April 2026: searches Roth conversion and drawdown strategies around IRMAA and ACA limits |
| Shows its methodology & what it won't model |
Yes — cited sources, published | Partial |
| Price / year | $132 | $129 |
ProjectionLab's price, account linking, data storage and optimizer checked against its own pages in September 2026; they change — check ProjectionLab for the current details. ZBee isn't affiliated with ProjectionLab.
Where ProjectionLab does more
Being straight about this: ProjectionLab lets you model open-ended what-if scenarios — career breaks, house purchases, alternate lives — with beautiful charts, and the FIRE community loves it for exactly that flexibility. Since April 2026 it also has an Optimizer that searches Roth conversion, drawdown and gain-harvesting strategies for you, working around Medicare IRMAA and ACA subsidy limits. If what you want is a rich sandbox for exploring futures, or software that picks a conversion strategy, ProjectionLab is built for that, and it's a fine reason to pick it.
Where ZBee is different
The deepest difference is what the numbers are built on. ProjectionLab has no account linking — your plan rests on figures you type and retype as markets move. ZBee connects read-only to your brokerage and pulls every actual position at your broker's latest synced prices, so the answer tracks what you really own without maintenance. The second difference is the kind of answer: a sandbox gives you outcomes for the scenarios you think to build; ZBee gives you a measured spending number with this year's trim-and-raise trigger points in dollars, and automatically replays that number through every real market sequence since 1928 — no scenario setup required. And ZBee is a native Mac app rather than a web app, with the platform look, feel, and offline independence that implies.
ZBee has no optimizer of any kind, and that is a position rather than a gap. It measures what your current situation supports: enter the Roth conversion plan you or your adviser chose and ZBee shows exactly what it does, year by year, taxes included. Recommending restructurings is advice territory it stays out of. The full comparison covers this line-drawing in detail.
Planned life events are inputs, not scenarios
A distinction that's easy to miss when weighing the two: most of what a near-retiree wants to "model" isn't an alternate life — it's the life they're already planning. Downsizing the house at 75, a gift to a child in 2028, a new roof, part-time work for the first few years, higher health or care costs late in the plan: in ZBee those are ordinary Money in / Money out rows in the one plan — an amount and the years it applies. The year-by-year table works out their consequences (taxes included), the spending chart shows a one-time expense standing out against the steady baseline, and the safe-spend number re-solves with them in.
What ZBee deliberately doesn't have is a scenario library — parallel alternate lives, career-break branches, a move-between-states planner. Exploring futures you may never choose is ProjectionLab's home turf. If an event is real enough to plan around, it belongs in the plan — and the decisions that remain genuinely open (when to retire, when to claim Social Security, what to leave behind) get their own side-by-side readout on ZBee's Trade-offs screen.
Which should you choose?
Choose ProjectionLab if you enjoy building and comparing life scenarios, want
maximum modeling freedom, and don't mind keeping the inputs current by hand.
Choose ZBee if you want one trustworthy number measured from your actual
accounts, kept current automatically, on your own machine. The two philosophies are different
enough that trying both is cheap: ZBee is free for 30 days on your own numbers — every
feature, no account — a fair place to see the difference for yourself.
See pricing · The full comparison · ZBee vs Boldin · ZBee vs Pralana · ZBee vs cFIREsim · ZBee vs WealthTrace · Guyton-Klinger spending guardrails · How much can you safely spend? · Read the methodology