Engineering & Science calculators
Choose a task below. Check each calculator’s assumptions and units before using its result.
HCl Acid Dissolving Power Calculator - Carbonate Rock
Determine the gravimetric (β) and volumetric (X) dissolving power of hydrochloric acid on calcite (CaCO3) and dolomite (CaMg(CO3)2) rocks.
Head Injury Criterion HIC Calculator
Crash biomechanics: Calculate HIC₁₅ and HIC₃₆ from head acceleration pulses, contact duration (t₂ - t₁), and probability of severe traumatic brain injury (AIS ≥ 4).
Heap Leach Irrigation & Recovery Calculator
Hydrometallurgy & extraction: Calculate cyanide/acid irrigation flow, kinetic metal extraction curves, reagent inventory, and pregnant leach solution (PLS) tenor.
Heat Exchanger Effectiveness Calculator - NTU Method
Model heat exchanger performance with the ε-NTU method: determine thermal effectiveness, maximum heat transfer, and hot and cold stream outlet temperatures.
Heat Exchanger Fouling Calculator - Derating Sizing Margin
Determine clean versus fouled overall U-values, total fouling resistance (Rf), required excess surface area over-design margin, and cleanliness factors per TEMA.
Helical Strakes Vortex Suppression Calculator
Aerodynamic VIV Suppression: Sizing Scruton 3-start helical strakes (pitch, height, coverage) and estimating drag penalty for circular chimneys and towers.
Helium Leak Detector Rate Calculator
Nondestructive testing & vacuum integrity: Calculate calibrated helium leak rates ($Q_{He}$), conversion to equivalent standard air leak rates ($Q_{air}$), and accumulation volume rise.
Helium Leak Rate Calculator - Vacuum Sniffing Sensitivity
Convert leak rates across standards (mbar·L/s, Pa·m³/s, atm·cc/s), calculate sniffing accumulation, and convert between tracer gases per ASTM E498/E499.
Helmholtz Resonator & Bass Trap Calculator
Studio acoustics & noise control: Design tuned narrow-band acoustic absorbers, perforated panel resonators, and slotted bass traps for room mode absorption.
Hemodialyzer Urea Clearance & KoA Calculator
Biomedical transport phenomena & artificial organs: Calculate diffusive solute clearance ($K$), mass transfer-area coefficient ($K_0 A$), and $Kt/V$ adequacy using the Michaels countercurrent dialyzer equation.
HEPA Single Fiber Filter MPPS Calculator
Cleanroom air filtration physics: Compute single-fiber capture efficiencies for Brownian diffusion ($\eta_D$), direct interception ($\eta_R$), and inertial impaction ($\eta_I$) to locate the Most Penetrating Particle Size (MPPS).
Hepatic Clearance Michaelis-Menten Calculator
Determine hepatic intrinsic clearance ($CL_{int}$), well-stirred liver model clearance ($CL_H$), hepatic extraction ratio ($E_H$), and first-pass oral bioavailability ($F_H$).
Herringbone Chaotic Micromixer Calculator
Laminar microfluidics & liposome synthesis: Model chaotic advection mixing length ($L_{mix}$), Péclet number ($Pe$), cycle periods, and exponential striation thinning in Stroock herringbone channels.
Herschel-Bulkley Mud Rheology Calculator - YPL Flow n K
Compute 3-parameter Yield Power Law (YPL) rheology (yield stress τ₀, flow index n, and consistency index K) across low and high shear rate regimes.
Hertz Wheel-Rail Contact Stress Calculator
Railway geomechanics & vehicle-track interaction: Calculate elliptical Hertzian contact patch semi-axes ($a, b$), peak normal pressure ($p_0$), subsurface shear stress ($\tau_{max}$), and rolling contact fatigue (RCF) shakedown index.
High Shear Mixer Tip Speed Calculator - Shear Rate Gap
Calculate rotor-stator high-shear mixer peripheral tip speed, shear rate in the narrow rotor-stator gap, shear stress, and droplet deagglomeration metrics.
High Voltage Corona Loss Peek Formula Calculator
Determine disruptive critical voltage, fair and foul weather corona active power losses, and bundle conductor gradient mitigation via Peek's classic empirical formula.
Hip Replacement Femoral Stem Stress Calculator
Orthopedic implant engineering: Calculate cantilever bending stresses, peak tensile stress at the lateral stem neck, and fatigue safety factors per ISO 7206-4 / ISO 7206-6 standards.
Hoek-Brown Rock Mass Strength Calculator
Geotechnical engineering & underground mining: Compute Generalized Hoek-Brown (2002) non-linear failure envelope, rock mass compressive and tensile strengths, deformation modulus ($E_{rm}$), and equivalent Mohr-Coulomb parameters.
Hohmann Transfer Delta-V Calculator
Orbital Mechanics & Astrodynamics: Compute two-impulse Hohmann transfer $\Delta v_1$, $\Delta v_2$, total $\Delta v$, time of flight ($t_{tx}$), and rendezvous phase angle ($\phi$).
Hohmann Transfer Orbit Calculator
Astrodynamics & orbital mechanics: Calculate insertion burns Δv₁ and Δv₂, transfer ellipse semi-major axis, time of flight (TOF), and rendezvous phase angle.
Hollomon-Jaffe Tempering Parameter Calculator
Heat Treatment Engineering: Compute the Hollomon-Jaffe parameter ($HP$), evaluate time-temperature equivalence, and predict tempered steel hardness ($HRC$).
Horner Plot DST Permeability Calculator
Well testing & transient pressure analysis: Compute formation permeability (k), skin factor (s), initial reservoir pressure (P*), and radius of investigation from Horner buildup test slopes.
Horner Plot Pressure Transient Calculator
Compute formation permeability-thickness ($k \cdot h$), near-wellbore skin factor ($s$), and extrapolated initial pressure ($p^*$) from semilog Pressure Buildup Tests (PBT).
Hot Isostatic Pressing HIP Calculator
Predict hot isostatic pressing (HIP) densification: Final relative density (\(\rho_{rel}\)), hold time, pore closure kinetics, and creep deformation.
HRSG Attemperator Spray Calculator - Steam Desuperheater
Calculate boiler and HRSG desuperheater attemperator spray water flow rate (kg/h and lb/hr), thermal energy balance, and steam temperature regulation.
HRSG Duct Burner Calculator - Supplemental Firing Sizing
Calculate supplemental duct burner fuel firing duty (MMBtu/hr and MWth), turbine exhaust gas temperature rise, and added steam generation per ASME PTC 4.4.
HRSG Pinch Point & Approach Temperature Calculator
Determine evaporator pinch temperature difference, economizer approach margin, high-pressure steam generation, and boiler exhaust stack temperature.
HRSG Pinch Point Calculator - Approach Temperature Sizing
Calculate evaporator pinch point (ΔTpinch), economizer approach temperature (ΔTapproach), heat transfer surface trade-offs, and steaming prevention in HRSG boilers.
HTST Milk Pasteurization Calculator - Heat Regeneration
Model dairy HTST pasteurizer heat regeneration efficiencies, holding tube hydraulic residence times, auxiliary heating steam duties, and terminal cooling tons.
Hull Cell Current Distribution Calculator
Electroplating Quality Control: Predict local current density $J(x)$ across the standard 267 mL trapezoidal Hull Cell test coupon and pinpoint optimal operating ranges.
HVDC Converter Commutation Overlap Calculator
HVDC Transmission Systems: Compute thyristor commutation overlap angle ($\mu$), DC output voltage ($V_d$), and reactive power demand in 6-pulse/12-pulse converters.
Hydrate Formation Calculator - Gas Pressure & Temperature
Estimate equilibrium hydrate formation temperature (EHT) and dissociation pressure across sweet natural gas compositions and subsea tieback conditions.
Hydrate Inhibitor Calculator - MEG & Methanol Hammerschmidt
Determine required weight percentage and daily volumetric injection rate of Monoethylene Glycol (MEG) or Methanol to prevent gas hydrate blockages.
Hydrate Plug Dissociation Time Calculator
Flow Assurance Remediation: Calculate dissociation time, radial heat influx from seawater, latent melting energy, and gas release during subsea pipeline depressurization.
Hydraulic Accumulator Calculator - Precharge Volume Sizing
Size gas-charged hydraulic bladder and piston accumulators for emergency power, leakage makeup, and pulsation dampening using polytropic gas expansion.
Hydraulic Cylinder Calculator - Force Speed Flow Sizing
Determine hydraulic actuator push and pull force (tons & lbs), extension and retraction speeds, flow consumption (GPM), and cycle times.
Hydraulic Cylinder Calculator - Push Pull Force & Speed
Determine extension (push) and retraction (pull) forces in pounds and tons, cylinder speeds, rod annular areas, and cycle times.
Hydraulic Fracturing HHP Calculator - Pump Horsepower
Determine surface treating pressure (STP), required hydraulic horsepower (HHP), and pumping fleet truck counts for high-rate slickwater and gel frac jobs.
Hydraulic Hose Sizing Calculator - Velocity Drop Sizing
Size hydraulic suction lines, pressure lines, and return hoses to prevent pump cavitation and minimize line friction losses per ISO 4413 standards.
Hydraulic Hose Velocity Calculator - Dash Size & Flow
Calculate fluid flow velocities (ft/sec), determine proper dash size hoses, and prevent destructive pump inlet cavitation and excessive backpressure.
Hydraulic Pump Calculator - Flow Displacement Power Sizing
Compute hydraulic pump delivery flow (GPM & L/min), electric motor drive horsepower (HP & kW), and input shaft torque across gear, vane, and piston pumps.
Hydraulic Pump Horsepower Calculator - GPM & Displacement
Determine pump output flow rate (GPM), displacement per revolution, required electric or gas drive engine horsepower, and heat generation.
Hydraulic Reservoir Calculator - Tank Volume Oil Sizing
Size industrial hydraulic reservoir tanks (2x to 5x pump GPM), deaeration dwell time, natural surface heat dissipation, and supplementary oil cooler capacity.
Hydraulic Tank Size Calculator - Reservoir Gallons & Heat
Determine hydraulic reservoir capacity in gallons, oil dwell time for air separation, cylinder volume differentials, and natural heat dissipation.
Hydro Penstock Economic Diameter & Sizing Calculator
Balance capitalized value of lifetime head loss against penstock capital manufacturing cost using standard Adams, Sarkaria, and USBR formulas.
Hydro Surge Tank Stability Calculator - Thoma Oscillation
Calculate Thoma minimum surge tank stability area, Franke safety factor, maximum load rejection upsurge height, and oscillation period per Jaeger & Franke.
Hydrocarbon Dew Point Cricondentherm Calculator
Determine phase envelope cricondentherm temperature, cricondenbar pressure, pipeline operating hydrocarbon dew point, and retrograde condensation risk.