Named methods, visible limits
Estimate a measurement without hiding the assumptions.
Use browser-local tools that identify the equation, explain how to collect inputs, and keep uncertainty beside the result.
Available now
Health estimators with inspectable methods
Inputs stay in the browser and are not added to a shareable result URL.
Estimate the presumed ovulation day, six-day fertile window and next period for a regular cycle, with an eligibility check first. Not birth control.
Open tool Body Fat CalculatorEstimate adult body-fat percentage from tape measurements with a named historical circumference equation, clear measurement steps, and visible limits.
Open tool Body Shape CalculatorCompare bust, waist, high-hip and hip measurements with a named nine-category apparel model, including transparent overlap and no-match results.
Open tool mg to mL CalculatorCalculate mL from mg only with a label concentration or material density, using separate modes, visible arithmetic, and no medicine or water preset.
Open toolInterpretation boundary
A calculator result is not a clinical assessment.
Population-derived equations can be useful for a consistent estimate, but their error can vary by person and circumstance. Pages in this section cite their methods, identify excluded or sensitive populations, and avoid turning one result into a health verdict.
Common questions
Are these tools medical advice?
No. Each calculator explains its equation and limits, but it cannot diagnose a condition or replace individual clinical guidance.
Are my health measurements uploaded?
No. Tool calculations run in your browser, and entered measurements are excluded from ToolNeko analytics and page URLs.