Math & Numbers
Estimate the cooling load of a room by the simplified ASHRAE steady-state method. Transmission sensible load Q_trans = Σ(A_i·U_i·ΔT) over envelope surfaces entered one per line as 'area,U' (U in W/(m²·K)). Infiltration/ventilation sensible Q_s = 1.23·ACH·V·ΔT and latent Q_l = 3010·ACH·V·ΔW (W), where ΔW is the indoor-outdoor humidity-ratio difference derived from dry-bulb temperature and relative humidity via the Magnus saturation fit. Total cooling load = total sensible + total latent. Temperature in °C/K/°F (only differences matter), area in m²/ft².
cooling-load-calculatorMath & Numbers
Compute the Coefficient of Performance (COP) of a chiller / heat pump: COP = Q_c / W, where Q_c is the cooling capacity and W the work input (both in consistent power units; COP is dimensionless). Three modes: solve COP (given Q_c and W), solve cooling capacity (given COP and W), or solve input power (given COP and Q_c). Capacity in W/kW/BTU·h⁻¹/ton/kcal·h⁻¹, power in W/kW/hp; all converted to W internally.
cop-calculatorDesign
Convert a color between HEX, RGB, HSL, CIELAB, and Display-P3 with CSS-ready output and gamut checks.
color-space-converterMath & Numbers
Estimate copper cable current-carrying capacity per the simplified IEC 60364-5-52 reference method. Combines cross-section, insulation (PVC 70°C / XLPE 90°C), installation method, and ambient temperature to derive the corrected allowable ampacity (A).
cable-ampacity-calculatorMath & Numbers
Compute the reactive power produced by a known capacitor: Q_c = 2π·f·C·U². Supports single-phase, three-phase star (Y) and delta (Δ) connections. Returns Q_c in var/kvar, capacitive reactance Xc, and capacitor current Ic. Complementary to the power-factor-correction tool (which sizes a capacitor for a target cosφ).
capacitor-reactive-powerMedia
Preserve SDR AVIF sample precision in a verified 16-bit-per-channel PNG container.
avif-to-16bit-pngMath & Numbers
Calculate support reactions of a simply supported beam via static equilibrium. UDL: RA=RB=q·L/2. Center point load: RA=RB=P/2. Off-center point load at a: RA=P·b/L, RB=P·a/L. Also returns max shear Vmax and max moment Mmax.
beam-reaction-forceMath & Numbers
Calculate the Terzaghi ultimate bearing capacity of a shallow foundation: q_ult = c·Nc·sc + q·Nq·sq + 0.5·γ·B·Nγ·sγ. Computes Nc/Nq/Nγ and shape factors automatically; supports strip, square, and circular footings. Result in kPa.
bearing-capacity-calculatorMath & Numbers
Calculate the Euler critical buckling load of an axially loaded column: P_cr = π²·E·I/(K·L)². Supports pinned-pinned (K=1), fixed-free (K=2), fixed-pinned (K=0.7), fixed-fixed (K=0.5). Returns effective length, radius of gyration, slenderness ratio λ, and critical stress σ_cr.
column-buckling-loadMath & Numbers
Convert between concrete strength notations: C grade ↔ cube strength fcu ↔ cylinder fck,cyl ↔ prism fck,prism ↔ design value fc. Ratios: fck,cyl = 0.8·fcu, fck,prism = 0.88·0.76·fcu, fc = fck,prism/1.4. Any one input produces all others.
concrete-strength-grade-converterMath & Numbers
Calculate the maximum bending (flexural) stress σ_max = M·c/I = M/Z at the outermost fiber of a beam section. Supports solid circle, rectangle, hollow tube, and I-beam; computes I, section modulus Z, and distance c automatically. Stress in MPa.
bending-stress-calculatorMath & Numbers
Calculate the maximum bending moment M_max, maximum shear force V_max and free-end deflection δ_max of a cantilever beam under a free-end point load P or a uniformly distributed load q. Point load: δ = PL³/(3EI); UDL: δ = qL⁴/(8EI).
cantilever-beam-calculator