Science & Education

Calculate microscope object scale, field of view, diffraction limits, Nyquist sampling, and download a transparent SVG scale bar.

Health

Calculate MAP = DBP + (SBP − DBP)/3. Normal 70–100; ≥65 sepsis target; <65 hypoperfusion. Derived from Geddes 1984, SSC 2021, BTF 2017, StatPearls, LITFL. Not medical advice.

Health

Analyze Mean Platelet Volume (MPV) in fL, an index of platelet production kinetics. Reference range ≈ 7.5–11.5 fL (lab- and method-dependent). Low MPV (< 7.5 fL, small old platelets) indicates suppressed marrow production (aplastic anemia, chemotherapy/radiation, recent platelet transfusion, iron-deficiency regeneration, Wiskott-Aldrich). High MPV (> 11.5 fL, large young platelets) indicates peripheral destruction with compensatory turnover or macrothrombocytopenia (immune thrombocytopenia ITP, post-splenectomy, myeloproliferative neoplasms, severe sepsis in recovery, Bernard-Soulier / MYH9, megaloblastic anemia; elevated MPV after acute MI marks platelet activation and adverse prognosis). Optionally enter the platelet count to refine the differential: low platelets + high MPV → peripheral destruction; low + low → underproduction; high + low → reactive thrombocytosis; high + high → myeloproliferative neoplasm. Pre-analytical caveat: platelets swell in EDTA over ~2 h raising MPV, and values are method-dependent (impedance > optical > immuno) — compare within the same lab and analyzer. Derived from Bath 1996, Leader 2012, Vagdatli 2010, and MDCalc. Not medical advice.

Health

Convert bidirectionally between a prescribed clinical dose and an infusion-pump rate (mL/hr). Supports weight-based (mcg/kg/min, mg/kg/hr, units/kg/hr) and flat (units/hr) dosing. Two directions: Dose → Rate and Rate → Dose. ALL high-alert infusions require independent double-checking (ISMP). Derived from Macklin 2011, ISMP, Royal Marsden 9th ed. 2015, and MDCalc. Not medical advice.

Health

Calculate the UNOS/OPTN MELD-Na score — the sodium-modified MELD used for adult liver transplant allocation in the US from January 2016 until superseded by MELD 3.0 in July 2023. First compute the base MELD(i) (same formula as MELD, clamped 6–40). If MELD(i) > 11: MELD-Na = MELD(i) + 1.32·(137 − Na) − 0.033·MELD(i)·(137 − Na), with sodium clamped to 125–137 mmol/L. If MELD(i) ≤ 11, MELD-Na = MELD(i) (no sodium adjustment). The result is rounded and clamped to 6–40. Rationale: hyponatremia (Na < 137) predicts worse waitlist mortality beyond what MELD(i) captures, so the score is inflated; the interaction term scales the sodium penalty down at very high MELD(i). Derived from Kim/Biggins 2008 (NEJM) and UNOS/OPTN policy. Not medical advice.

Health

Calculate the current UNOS/OPTN base MELD(i) score for end-stage liver disease and transplant allocation: MELD(i) = (0.957·ln(creatinine) + 0.378·ln(bilirubin) + 1.120·ln(INR) + 0.643) × 10, rounded and clamped to 6–40. Creatinine is floored at 1.0, capped at 4.0 mg/dL, and forced to 4.0 if dialyzed ≥2× or on CVVHD ≥24 h in the past week; bilirubin and INR are floored at 1.0. NOTE: in the US, MELD-Na (2016) and then MELD 3.0 (Jul 2023, adds sex and albumin) have superseded this base MELD for adult allocation — this tool implements the classic base MELD(i) for education / non-US use. Derived from Kamath 2001 (Hepatology) and UNOS/OPTN policy. Not medical advice.

Math & Numbers

Calculate the efficiency of a mechanical transmission (gearbox, belt, chain, etc.). η = P_out / P_in, returning the efficiency percentage and the power loss P_loss = P_in − P_out.

Utilities

Find meeting windows where 2–6 participants across time zones are all working. Computes UTC intersection, ranks by comfort, exports .ics.

Games

Classic Mastermind code-breaking game. The computer picks a secret color code; you guess row by row. Black pegs = right color and position; white pegs = right color, wrong position.

Games

Classic memory matching game. Flip cards two at a time to find matching pairs; tracks moves and time, then grades you. Easy / standard / hard grids, emoji or number card faces.

Media

Extract audio/video metadata as JSON with ffprobe.

Science & Education

Build a Punnett square for a Mendelian cross and auto-calculate genotype and phenotype ratios. Supports complete dominance, incomplete dominance (blending), codominance, and X-linked (sex-linked) inheritance — with each offspring cell's sex marked for X-linked crosses.