Budget calculators
Decide where every unit goes before the month decides for you.
The Brink Labs
Private, offline-first money software Built Offline, On Purpose.
The Brink Labs builds personal finance software that runs on your own device. Ten calculators work entirely in your browser without sending a single figure to a server, and MyneWallet — a private, offline expense tracker and zero-based budget planner for Android — keeps your ledger on your phone, with encrypted backups. No account, no advertising, no subscription.
Nothing uploadedNo cookiesBought once, never rented
0figures sent to a server. See exactly what this site does
10instruments, each checked against a second, independently written implementation
1payment for MyneWallet’s full engine, if you want it. Never a subscription
The Instruments
Ten Calculators.
Four Questions.
Plan, protect, borrow, grow. Each instrument runs entirely inside your browser, opens on a worked example, and publishes the formula it runs.
Leaks, buffers and sinking funds
Find the leaks, build the floor, and fund the costs you can already see coming.
Loan and debt calculators
Price the loan before you sign it, and clear the debt in the cheapest order.
Growth and net worth calculators
See how fast money compounds, and where your net worth is heading.
MyneWallet
Android · Live on Google Play
MyneWallet is a private, offline expense tracker and zero-based budget planner for Android. It never asks for a bank login, keeps your ledger on your phone, and works fully in airplane mode.
- Zero-based envelope budgeting — every unit of income assigned before it is spent.
- Two-tap capture — no network round-trip between spending and logging.
- An analysis engine, not a pie chart — net worth, obligations and a 30-day outlook.
- Encrypted backups — AES-256-GCM on your phone, to your own Google Drive or a file you keep.
Free to use. One-time unlock for the full engine. No subscription, ever.
Read what it refuses to do →
The Doctrine
Four Commitments,
Written As Constraints.
A principle you can break at will is a preference. These four are written into the architecture, which is what makes them checkable rather than reassuring.
On-device by default
If a feature can run on the phone, it runs on the phone. The network is a privilege we ask permission for, never an assumption we design around. This is why there is no sync: a copy you cannot see is still a copy.
Bought once, owned forever
A tool you open daily makes an excellent subscription and a poor deal. We charge once. If the company disappears tomorrow the software keeps working, because nothing about it depends on us still being here.
No advertising, no telemetry
There is no analytics SDK, no attribution SDK and no crash reporter phoning home. We do not know how many screens you opened today, and we have built ourselves no way of finding out.
Correct before clever
Arithmetic about somebody’s money is not a place for approximately. Every figure is checked against an independent implementation before it ships, and a feature waits if the maths is not settled.
A privacy policy is a promise about what a company will choose to do.
An architecture is a statement about what is possible.
Engineering Standard
Tested Like Infrastructure,
Not Like An App.
Personal finance software fails quietly. A wrong figure looks exactly like a right one, so the only defence is refusing to trust the first implementation of anything.
1,100+
Automated tests on every MyneWallet release, covering the arithmetic, the entitlement
caps and the import engine.
2×
Every instrument’s maths is verified against a second, independently written
implementation before it ships.
0
Tracking SDKs in the app. No advertising, attribution, analytics or crash-reporting SDK;
the only third-party code is Google’s own sign-in, Drive, Play Billing and Play review libraries.
100
Lighthouse accessibility on every page of this site, with contrast solved against the
tinted surfaces, not just the flat ones.
Questions
The Brink Labs, Answered Plainly.
What is The Brink Labs?
The Brink Labs is a small software lab that builds personal finance tools which run on your own device. It publishes MyneWallet, a private, offline expense tracker and zero-based budget planner for Android, and ten private finance calculators on this website. Everything is designed so your financial data never needs to leave your phone or your browser.
What does offline-first mean?
Offline-first means the software does its job without a network connection and treats the internet as optional. MyneWallet stores your ledger on your phone and works in airplane mode; the calculators on this site run in your browser and send nothing anywhere. The practical result is that no server of ours holds a copy of your finances, so there is nothing for us to breach, sell or lose.
How does The Brink Labs make money?
MyneWallet is free to use, and an optional one-time unlock opens its full engine. That is the only source of revenue. There is no advertising, no data sale, no affiliate link and no subscription — which is also why the calculators on this site have no reason to collect anything from you.
Is MyneWallet available on iPhone?
No. MyneWallet is currently available for Android only, through Google Play. The ten instruments on this website work on any device with a modern browser, including iPhone and iPad, and need no account.
Can I check that the calculators send nothing?
Yes, in about ten seconds. Open your browser's developer tools, choose the Network tab, and type figures into any instrument: no request carries them, because there is no endpoint to receive them. The Application tab shows no cookies and no stored figures. The methodology page lists exactly what this website does and does not do.
Where To Start
Stop Renting.
Start Owning.
If you want to see how we build before you install anything, the instruments are the honest preview: same architecture, same refusal to phone home, no sign-up to find out.
The Brink LabsCurrently
ShippingMyneWallet for Android
Instruments live10
Servers holding your dataNone
Subscriptions soldNone