Trusted formulas · US · UK · Canada
Financial calculators that are fast, accurate, and clear
FiscalModus helps SaaS founders model unit economics and homebuyers estimate mortgage and tax scenarios — with transparent methodology and YMYL-compliant disclaimers.
SaaS unit economics
Global tools for runway, CAC, LTV, churn, and pricing — ideal for founders in the US, UK, and Canada.
SaaS Runway Calculator
Estimate months of runway from cash and burn rate.
Open calculator →SaaS Burn Rate Calculator
Calculate monthly net cash burn for your startup.
Open calculator →SaaS CAC Calculator
Customer acquisition cost from spend and new customers.
Open calculator →SaaS LTV Calculator
Lifetime value from ARPU and churn.
Open calculator →LTV:CAC Ratio Calculator
Compare lifetime value to acquisition cost.
Open calculator →SaaS Churn Calculator
Monthly and annual churn from customer counts.
Open calculator →US mortgage cluster
Payment, amortization, refinance, and extra-payment scenarios for US home loans.
Mortgage Calculator
Full payment breakdown with taxes and insurance.
Open calculator →Mortgage Payment Calculator
Principal and interest payment only.
Open calculator →Amortization Calculator
Year-by-year loan balance and interest.
Open calculator →Refinance Calculator
Compare current vs new loan and break-even.
Open calculator →Extra Payment Calculator
See payoff time saved with extra payments.
Open calculator →UK mortgage & stamp duty
Repayment and interest-only calculators plus SDLT for England & Northern Ireland.
UK Mortgage Calculator
Repayment or interest-only monthly payment in GBP.
Open calculator →UK Mortgage Payment Calculator
Principal and interest for UK repayment mortgages.
Open calculator →UK Stamp Duty Calculator
Estimate SDLT on England & Northern Ireland purchases.
Open calculator →UK Amortization Calculator
Repayment schedule for UK fixed-rate mortgages.
Open calculator →Canada mortgage & CMHC
5-year fixed payments with amortization and default insurance estimates.
Freelancer & self-employed tax
Country-specific tax estimators — US 1099, UK Self Assessment, and CRA T2125.
1099 Tax Estimator
Self-employment tax, federal income tax, and quarterly payments.
Open calculator →Quarterly Tax Estimator
IRS estimated tax payments for freelancers and contractors.
Open calculator →Self-Employed Tax Calculator
HMRC Self Assessment income tax and Class 4 NIC.
Open calculator →Self-Employed Tax Calculator
CRA T2125 estimate with CPP and quarterly instalments.
Open calculator →Why FiscalModus exists
Financial decisions deserve more than a black-box widget. FiscalModus publishes the formulas behind every tool, links to official sources, and separates estimates from professional advice — especially on tax and mortgage pages where mistakes are costly.
Whether you are a SaaS founder modeling runway before a board meeting or a first-time buyer comparing 30-year mortgage scenarios, you get the same transparent approach: inputs you control, outputs you can verify, and methodology you can read before you trust the number.
Who these tools are for
SaaS unit economics calculators serve founders, operators, and investors worldwide — metrics like CAC, LTV, and runway apply regardless of where your company is incorporated.
Mortgage and tax tools are scoped by country (US, UK, Canada) because rates, insurance rules, and filing requirements differ. Each page states its jurisdiction in the header badge and disclaimer.
How we maintain accuracy
Calculator logic lives in tested TypeScript modules. Tax brackets and standard deductions are updated when official agencies publish new figures. See our methodology page for formula details and last-updated dates.
These tools produce estimates only. For binding loan quotes, tax filings, or investment decisions, work with licensed mortgage brokers, CPAs, and financial advisers who know your full situation.