Media
Convert GIF images to WebP format with quality settings and transparency support
gif-to-webpGeography
Calculate the shortest distance between two points on Earth using the great circle formula
great-circle-distanceText Processing
Convert halfwidth characters to fullwidth characters for CJK text formatting
halfwidth-to-fullwidthFormat Conversion
Convert GraphQL query or response data to JSON format
graphql-to-jsonMath & Numbers
Convert US liquid gallons to liters with configurable decimal precision
gallon-to-literScience & Education
r_s, r_p, R_s, R_p, T = 1−R, and the Brewster angle for any dielectric interface, with the 4% normal-incidence anchor.
fresnel-equationsEducation
One value, three linked notations — pie, bar, percent grid and number line — with a live-synced slider, exact repetend detection and practice exercises.
fraction-decimal-percent-visualizerEducation
Binomial retention probability 1 − (1−p)^(2N) for an allele among N founders, expected copy number, drift variance, copy-number distribution, and neutral fixation probability. Derived from Mayr 1942, Hartl & Clark 2007, StatPearls. Educational use only.
founder-effect-probabilityEducation
Estimate penetrance f = affected carriers / total carriers with nonpenetrance, plus a severe/moderate/mild expressivity breakdown among affected carriers. Derived from Wright, Griffiths, OMIM, StatPearls. Educational use only.
gene-penetrance-calculatorEducation
Compute genotype frequencies from counts: freq = count / N. Also derives allele and phenotypic frequencies. Derived from Hartl & Clark 2007, Griffiths, StatPearls. Educational use only.
genotype-frequency-calculatorHealth
Compute FFR = Pd / Pa (at maximal hyperemia). >0.80 non-ischemic; ≤0.80 PCI indicated. Derived from Pijls 1996, FAME, FAME 2, ESC/EACTS 2018, ACC/AHA 2021, StatPearls. Not medical advice.
fractional-flow-reserveHealth
Calculate solute-free water clearance (C_H₂O) and electrolyte-free water clearance (eC_H₂O) to differentiate hypo-/hypernatremia. Classic: C_H₂O = V·(1 − U_osm/P_osm); positive = dilute urine excreting free water (diabetes insipidus, polydipsia, water-load recovery), negative = concentrated urine conserving free water (dehydration, SIADH). Electrolyte-free: eC_H₂O = V·(1 − (U_Na + U_K)/P_Na), which better predicts the direction of serum sodium change — a negative eC_H₂O means the urine is electrolyte-free-water-rich and tends to raise serum Na⁺, informing IV fluid choice. Optional Na/K inputs enable the electrolyte-free calculation. Derived from Rose, Shimizu 2002 (Nephron), and NephSIM. Point estimate; interpret with full clinical context. Not medical advice.
free-water-clearance