Health

Estimate creatinine clearance (CrCl) with the Cockcroft-Gault equation: CrCl (mL/min) = [(140 − Age) × Weight(kg)] / [72 × SCr(mg/dL)] × 0.85 if female. Choose the weight basis: Actual Body Weight (ABW), Ideal Body Weight (IBW, Devine 1974), or Adjusted Body Weight (AdjBW = IBW + 0.4 × (ABW − IBW), for obese patients). Optional SCr floor at 1.0 mg/dL for elderly / low-muscle-mass patients. Returns an UN-indexed CrCl in mL/min — the value drug-dosing tables use (for BSA-indexed eGFR use MDRD or CKD-EPI). Derived from Cockcroft & Gault, Nephron 1976. Valid for stable renal function in adults. Not medical advice.

Health

Calculate the absolute bioavailability F of an extravascular (typically oral) dose: F = (AUC_po · Dose_iv) / (AUC_iv · Dose_po), where AUC_po and AUC_iv are the areas under the concentration-time curve after oral and IV dosing, and the doses correct for any difference in amount administered. F is dimensionless and lies in [0, 1]; IV bioavailability is by definition 1, while oral F < 1 reflects incomplete absorption and/or first-pass metabolism. AUC can be in any consistent unit (e.g. mg·h/L) since it cancels out of the ratio. Valid only for linear pharmacokinetics, the same drug molecule, and doses within the linear range. Not medical advice.

Design

Convert HEX, RGB, HSL, and CMYK colors into all four representations.

Development

Parse cron and show the next run in natural language, local time, UTC, countdown seconds, and Unix timestamps.

Development

Compare JSON, YAML, TOML, and dotenv configurations by key path while ignoring ordering and formatting noise.

Math & Numbers

Convert angular velocity (angular speed) between radian per second (rad/s, SI base), revolutions per minute (rpm = 2π/60 rad/s), degrees per second (deg/s = π/180 rad/s), and hertz (Hz, used as revolution per second = 2π rad/s). Converts via rad/s to the target unit and lists all four equivalents. Note: 1 Hz in angular-frequency context means one full revolution per second, so 1 Hz = 2π rad/s ≈ 6.283185307 rad/s. Reference: vinyl LP 33⅓ rpm ≈ 3.49 rad/s, car engine idle ~800 rpm ≈ 83.8 rad/s.

Media

Separate a music mix into drums, bass, other, vocals, guitar, and piano, then download one ZIP.

Media

Measure and adjust vocal level relative to an instrumental bed, with a transparent loudness report.

Astronomy

Plan observations with local sidereal time, optional nutation, precessed coordinates, and altitude/azimuth slots.

Networking

Simulate AS_PATH loop detection, policy filtering, attribute changes, and deterministic best-path selection.

Finance

Explore how contributions, compounding, fees, and inflation shape investment growth year by year.

Media

Normalize a batch of podcast episodes, apply metadata and chapters, and package validated delivery files in one ZIP.