Toolbox
Every calculation. Zero guesswork.
A set of accounting calculators organized into purchasable packs, covering tax estimators, deduction calculators, payroll utilities, and loan amortization. There is no AI involved, just clean, repeatable math that gives the same answer every time you run it.
The Pack System
Start with the free pack, and add the others as your firm needs them.
Seven packs in total, organized by accounting domain. The Starter Pack is free with every Cairn subscription, and the firm can buy individual paid packs as the practice grows into the work they cover.
Starter Pack
FreeThree essential calculators that come free with every Cairn subscription, so the firm can try Toolbox in real client work before deciding to buy any paid pack.
Tax Pack
- Federal income tax estimator
- Quarterly estimated payments
- Capital gains calculator
- AMT worksheet
Deductions Pack
- Mileage deduction calculator
- Home office (simplified + regular)
- Section 179 depreciation
- Charitable contribution limits
Payroll Pack
- Net-to-gross calculator
- Employer cost calculator
- Federal withholding estimator
- Overtime calculator
Loans Pack
- Amortization schedule generator
- Loan comparison tool
- Interest rate converter
- Balloon payment calculator
Retirement Pack
- Required Minimum Distribution
- Social Security estimator
- Contribution limit reference
- Early withdrawal penalty
Business Pack
- Self-employment tax estimator
- Entity type comparison
- Quarterly payment scheduler
- Break-even analysis
The Difference
Tools produce numbers, professionals provide counsel.
Toolbox is the math layer of the Cairn suite, sitting alongside the apps that use AI for their work. Inside Toolbox, every result is reproducible and verifiable, so the same inputs always yield the same answer, and a CPA can defend the math to a client without hedging.
No AI
Every calculation produces the same result every time, with the same inputs always yielding the same outputs. There are no models, no probabilities, and no "it depends" answers. Run it twice and you get the same answer twice.
No Advice
Toolbox produces numbers, and what those numbers mean for a specific client remains the firm's professional judgment. The calculator tells you the mileage deduction figure, and you decide whether it actually applies to the situation in front of you.
Instant Results
Every calculator runs directly in the browser, with no waiting on a server and no internet connection required. Enter the values, get the result, and move on without losing a moment to network latency.
Clean inputs and clear outputs.
Every calculator follows the same pattern of labeled fields, instant results, and no extra clutter on the page. Enter the numbers you already know, and the answer you need lands without any further work.
Calculator packs
Individual calculators
AI dependencies
Ready to add Toolbox to your stack?
We're onboarding firms one at a time. Leave your info and we'll reach out.