Methodology and Sources

Where the numbers come from

Tax, retirement, and Medicare figures come from the current-year IRS revenue procedures (for 2026, Rev. Proc. 2025-32), SECURE 2.0 final regulations, the Social Security Administration COLA release, and the CMS Medicare Part B and Part D IRMAA tables. Each affected calculator states its source year in the on-page explainer.

Home project quantities use standard industry conventions: cubic-yard math (length x width x depth in feet, divided by 27), waste allowances that match common contractor rules of thumb, and material densities from USDA NRCS references and manufacturer bag labeling. We prefer conservative defaults so results tend to slightly over-order rather than run short.

How each calculator is built

1. A pure TypeScript math module holds the formula and unit conversions. It is written to be readable line by line so a reviewer can check every step.
2. A route page connects inputs to the math module and shows the intermediate values (area, cubic feet, waste-adjusted volume) alongside the headline result.
3. The assumptions block on each calculator restates every constant we used (density, waste, spacing) so the number is not a black box.

Review cadence

Tax and Medicare calculators are reviewed each January as new IRS and CMS numbers are published. Home project calculators are reviewed at least once a year and whenever a reader reports an issue or a source updates its published guidance.

Limitations

These are planning tools, not final estimates. Local codes, site conditions, current material prices, and personal circumstances always take precedence. A qualified contractor, tax professional, or advisor will refine the number for your specific situation.

Corrections

If you spot a formula, unit, or figure that looks wrong, please report it through the corrections page. Every report is reviewed and a change is logged on the updates page.