What Power of Interest provides
The site focuses on loan amortization, daily and per-diem interest, payoff calculations, private and seller-financed loans, payment coupons, mortgage payoff planning, and related interest mathematics. Free calculators are designed to answer a specific calculation clearly, while the Windows programs add workflows such as saving, reopening, printing, reporting, and managing larger sets of records.
Browser-based tools for interest, loan payments, payoff planning, annuities, debt, savings, and related math.
Focused desktop programs for editable amortization schedules, payoff worksheets, payment coupons, escrow analysis, and private-loan records.
Purchase, download, and registration questions can be handled by phone or email.
How calculators are built and reviewed
Each calculator is based on a stated mathematical method. Where conventions can change the answer—such as Actual/360 versus Actual/365, payment timing, compounding frequency, or date-count rules—the calculator should expose that assumption or explain it near the result. Worked examples are used to make the method easier to verify.
Financial contracts can contain rules that a general calculator cannot infer. For that reason, pages distinguish mathematical estimates from contract-specific, legal, tax, or servicing determinations. Users should compare the calculator assumptions with the governing agreement when the result will be used for a real transaction.
Editorial and calculation standards
- State the formula or method. Important calculations should identify the rate convention, timing, or day-count basis being used.
- Use examples. A worked example makes it easier to verify that a formula is being interpreted correctly.
- Separate free calculation from software workflow. A free calculator should answer the mathematical question; paid software adds saving, printing, reporting, or longer-term workflow features.
- Use primary sources where regulation controls. Regulatory topics such as RESPA or federal disclosures should be checked against the applicable official requirements.
- Correct errors. If a calculation, formula, or page appears incorrect, contact Power of Interest so it can be reviewed.
Company and support
Power of Interest is operated by ERICH Incorporated and has offered loan and interest software for many years. Current product pages show the available Windows software, one-time pricing, free evaluations, and registration steps.