Calculator Methods & Assumptions

What a result means

A calculator result is only as useful as the question, inputs, and assumptions behind it. Uzi Tools keeps the calculation in the browser and shows the main formula, intermediate values, or assumptions where the tool supports them. Exact arithmetic tools can still produce an unsuitable answer when the wrong units or model are entered.

Finance and budgeting

• Mortgage payments use standard fixed-rate amortization for principal and interest. Property tax and insurance are optional annual estimates divided across monthly payments.
• Compound-interest, SIP, and retirement tools project a constant return or interest assumption over the selected period. They do not predict markets, taxes, fees, or currency exchange.
• Paycheck, budget, debt, ROI, margin, and rent-versus-buy tools simplify the inputs so you can compare scenarios. They are not jurisdiction-specific tax, lending, investment, or legal tools.

Start with the finance and budgeting calculators and verify important figures with the lender, provider, or professional who owns the relevant rate or policy.

Health and fitness estimates

BMI, BMR/TDEE, body-fat, calorie, water, ideal-weight, sleep, pregnancy, and ovulation pages apply common formulas or calendar assumptions to the values entered. These results do not diagnose, treat, or rule out a medical condition. Body composition, medication, cycle variation, pregnancy history, and health status can make a simple formula a poor fit.

Use the health and fitness calculators as educational starting points and speak with a qualified health professional for personal decisions.

Converters, math, and project tools

• Unit, number-base, Roman-numeral, and date tools use explicit source and target conventions. Data-size conversion keeps decimal units such as MB separate from binary units such as MiB.
• Math pages use the displayed equation or method: for example, the quadratic solver shows the discriminant and formula substitution, while regression uses a least-squares line for the paired values entered.
• Paint, concrete, landscape, tire, auto, and solar tools estimate quantities or compare scenarios. Product coverage, waste, fitment, rates, local rules, and installation conditions can change the real-world result.

Browse the full calculator and converter directory to choose a page by the task you need to complete.

Privacy and updates

Tool inputs are processed on your device for calculation. Read the Privacy Policy for analytics and site-data details. If a formula, input range, or assumption changes, the relevant tool page should state that change in its visible explanation and examples.