Games

Shuffle a standard deck of playing cards

Health

Calculate pregnancy due date based on last period or conception date

Calculator

Calculate probabilities for dice rolls and combinations

Data Processing

Remove duplicate columns from CSV data with flexible detection strategies. Perfect for cleaning datasets, removing redundant information, and optimizing data structure. Features: - Detect columns with identical headers - Find columns with identical data content - Support for case-sensitive/insensitive matching - Multiple removal strategies available - Preserve data integrity - Support for large datasets - Fast and efficient processing Common Use Cases: - Clean up merged datasets - Remove redundant data columns - Optimize data for analysis - Prepare data for machine learning - Reduce file size and complexity - Standardize data format

Network

Query DNS records and domain resolution information including A, AAAA, MX, TXT, NS, and CNAME records

Math & Numbers

Calculate derivatives of common functions

Data Analysis

Comprehensive data distribution analysis with normality tests, outlier detection, and goodness-of-fit assessments

Utilities

Convert any date to its day-of-year number (1-366) and back, with ISO week number, leap-year check, and days remaining in the year.

Health

Calculate the CURB-65 score to assess community-acquired pneumonia (CAP) severity and guide the site of care. Each component scores 1 point: Confusion (new-onset disorientation), Urea > 7 mmol/L (BUN > 20 mg/dL), Respiratory rate ≥ 30/min, Blood pressure (systolic < 90 OR diastolic ≤ 60 mmHg), and Age ≥ 65. Range 0–5. Interpretation: 0–1 low risk (likely outpatient; 30-day mortality ~1.5–2.4%), 2 moderate (consider admission or supervised discharge, ~9.2%), 3–5 high risk (hospital admission; consider ICU for 4–5; mortality rises to ~57% at score 5). Endorsed by the British Thoracic Society. Derived from Lim et al. 2003 (Thorax). Not medical advice.

Health

Compare three pneumonia severity scores side-by-side from one set of inputs to support concordance reading. CURB-65 (0-5: Confusion, Urea, RR, BP, age ≥65) — quick bedside triage; PSI/PORT (Fine 1997, 5 risk classes) — the most accurate mortality stratification, more complex; SMART-COP (0-10, 2 points each for SBP <90 and hypoxia, 1 point each for multilobar CXR, albumin <3.5, RR ≥25, tachycardia ≥125, confusion, pH <7.35) — predicts need for ICU respiratory/vasopressor support. Each score has a different focus: CURB-65 is fast; PSI is more precise; SMART-COP identifies who needs ICU. The tool reports each score's total/category/interpretation and an agreement analysis (whether all three point to outpatient/admission/ICU). When scores disagree, favor the more conservative disposition. Derived from Lim 2003, Fine 1997, Charles 2008. Not medical advice.

Math & Numbers

Compute radial steady-state heat conduction through a single-layer cylindrical wall (Fourier's law in cylindrical coordinates): radial heat flow rate Q = 2π·k·L·ΔT/ln(r₂/r₁) (W), inner-surface heat flux q_inner = Q/(2π·r₁·L) (W/m²), outer-surface heat flux q_outer = Q/(2π·r₂·L) (W/m²), and cylindrical thermal resistance R = ln(r₂/r₁)/(2π·k·L) (K/W). k is the thermal conductivity (W/(m·K)); L the cylinder length; r₁ the inner radius, r₂ the outer radius (must have r₂ > r₁ > 0); ΔT the temperature difference (K; a °C difference equals a K difference, a °F difference is converted by ×5/9). ΔT may be negative (indicating reverse heat flow), but k, L, r₁ and r₂ must be positive. Length and radius in m/cm/mm.

Math & Numbers

Compute the back-EMF and electromagnetic torque of a DC motor from its machine constant: E=k·ω, T=k·I. In SI units the back-EMF constant equals the torque constant (k_e=k_t=k, V·s/rad=N·m/A). Also returns the mechanical (air-gap) power P=T·ω=E·I. Speed accepted in rad/s or RPM.