Health

Calculate the Urine Anion Gap (UAG) to differentiate causes of normal-anion-gap (hyperchloremic) metabolic acidosis: UAG = (U_Na + U_K) − U_Cl, in mmol/L. The UAG is an inverse surrogate for urinary NH₄⁺ excretion. A negative UAG (typically −20 to −50) indicates appropriate high NH₄⁺ excretion → extrarenal (GI) bicarbonate loss (diarrhea, fistulae, ureteral diversions). A positive/high UAG indicates low NH₄⁺ excretion → renal tubular acidosis (distal/type 1, type 4 hypoaldosteronism, proximal/type 2 variable). Reference range ≈ 0 to +40 mmol/L. Caveats: unreliable with unmeasured urine anions (ketoacidosis, toluene/hippurate, D-lactate) or when urine sodium < 25 mmol/L (use urine osmolar gap instead). Derived from Batlle CJASN 2012, Ito 2025, Bonner AJKD 2025. Interpret with blood gas and full clinical context. Not medical advice.

Health

Calculate the APACHE II (Acute Physiology and Chronic Health Evaluation II) ICU severity score. APACHE II = Acute Physiology Score (12 variables, each 0–4 using the worst value in the first 24 h) + Age points (0–6) + Chronic Health points (0/2/5). Range 0–71; higher scores indicate worse prognosis. Oxygenation uses the A-a gradient when FiO₂ ≥ 0.5, otherwise PaO₂. Creatinine points are doubled when acute renal failure is indicated. GCS contributes 15 − GCS. Also reports the base-model predicted mortality: R = 1/(1 + e^(−logit)), logit = −3.517 + 0.146 × score (diagnostic-category weight not included). Thresholds cross-verified against Knaus 1985 (Crit Care Med) and the SFAR scoring table. Not a substitute for clinical judgement. Not medical advice.

Health

Calculate the HAS-BLED score to estimate major bleeding risk in patients on oral anticoagulation (most commonly combined with CHA₂DS₂-VASc in atrial fibrillation). Each component scores 1 point: Hypertension (uncontrolled, systolic BP >160), Abnormal renal function (dialysis/transplant/Cr >2.26 mg/dL), Abnormal liver function, prior Stroke, prior major Bleeding/predisposition, Labile INR (TTR <60% on warfarin), Elderly (age >65), Drugs (antiplatelet/NSAID), Alcohol (≥8 drinks/week). Range 0–9 (renal/liver and drugs/alcohol can each contribute up to 2). Interpretation: 0 low, 1–2 moderate, ≥3 high risk — regular review and correct reversible factors; a high score alone does NOT justify withholding anticoagulation. Derived from Pisters 2010 (Chest) and the 2023 ACC/AHA/ACCP/HRS AF guideline. The 'labile INR' criterion mainly applies to warfarin users; predictive value is lower for DOACs. Not medical advice.

Development

Analyze Cache-Control directives, calculate browser/shared-cache TTL and stale budgets, detect directive conflicts, and compare static behavior notes for generic HTTP, Fastly, Cloudflare, and Akamai.

PDF Tools

Rasterize scanned PDF pages, recognize text with Tesseract, and export an editable DOCX.

Development

Decode 64-bit Snowflake-style IDs for Discord, Twitter, Mastodon, Sonyflake, Instagram, or a custom bit profile. Extract timestamp, worker/process/machine, sequence fields, align platform epochs, and infer a Discord shard when a shard count is supplied.

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

Estimate glomerular filtration rate (eGFR) in children (1–18 y) with the Schwartz formula. 2009 Bedside version (recommended, IDMS-traceable creatinine): eGFR = 0.413 × Height(cm) / SCr(mg/dL). 1984 Original version (legacy, pre-IDMS assays): eGFR = 0.55 × Height(cm) / SCr(mg/dL). The coefficient dropped from 0.55 to 0.413 because IDMS-standardized assays return lower creatinine values. Returns a BSA-INDEXED eGFR in mL/min/1.73 m². Derived from Schwartz GJ et al., Am J Kidney Dis 2009 (0.413) and Pediatrics 1976 (0.55). Valid for pediatric stable renal function; use CKD-EPI/MDRD for adults, not for neonates/AKI. Not medical advice.

Format Conversion

Encode or decode bytes with ZeroMQ Z85, RFC 1924 Base85 or a validated custom alphabet in single or line-batch mode

Development

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

Health

Calculate the continuous IV infusion rate that maintains a target steady-state plasma concentration: R₀ = Css · CL, where Css is the target concentration and CL is clearance. At steady state, the infusion rate equals the elimination rate. If the IV solution concentration (mg/mL) is provided, the tool additionally derives the infusion-pump delivery rate in mL/h, which is what the pump is actually set to in clinical practice. This is an IV-only tool — bioavailability F is not applicable. Reaching steady state requires approximately 4–5 half-lives. Not medical advice.

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.