Engineering & Science calculators
Choose a task below. Check each calculator’s assumptions and units before using its result.
Drilling Bit Hydraulics Calculator - Jet Impact Force HSI
Optimize roller cone and PDC bit cleaning: calculate Total Flow Area (TFA), nozzle velocity (ft/s), bit pressure drop, Hydraulic Horsepower (HHP), and HSI.
Drilling Mud Rheology & Pressure Drop Calculator
Determine Bingham Plastic ($PV, YP$) and Power Law / Herschel-Bulkley parameters ($n, K$), effective viscosity, and laminar/turbulent circulating pressure loss.
Drilling Riser Disconnect Watch Circle Calculator
Determine dynamic positioning (DP) drift-off velocities, Green/Yellow/Red watch circles, and emergency disconnect sequencing (EDS) margins before flex joint mechanical binding.
Drilling Riser VIV Calculator - Marine Current Lock-In
Assess ocean current VIV crossflow lock-in risk, shed vortex frequencies (fs), and fatigue mitigation via helical strakes per DNV-RP-F105 & API 16Q.
Drillstring Hookload & Buoyed Weight Calculator
Compute buoyancy factor ($BF$), total buoyed drillstring weight, static hookload, neutral point in tension/compression, and available Margin of Overpull ($MOP$).
Droplet Microfluidics Generator Calculator
Two-phase multiphase microfluidics: Model droplet diameter ($d_{drop}$), generation frequency ($f$), Capillary number ($Ca$), and pinching regimes (squeezing vs dripping).
Drug Bioavailability AUC Calculator
Determine absolute systemic bioavailability ($F$), numerical Area Under the Curve ($AUC_{0-\infty}$), peak concentration ($C_{max}$), and clearance ratios.
Drug Dissolution Kinetics Calculator
Fit solid dosage release profiles using Weibull, Hixson-Crowell, and Higuchi models, and compute FDA similarity ($f_2$) and dissimilarity ($f_1$) factors for bioequivalence.
Drying Time Calculator - Constant and Falling Rate Period
Calculate batch tray and conveyor drying durations, constant rate surface evaporation time, internal diffusion falling rate time, and total batch cycle time.
Duct Equal Friction Calculator - CFM Velocity Sizing
Size circular and rectangular air distribution ducts using the standard ASHRAE equal friction method with velocity, aspect ratio, and noise guidelines.
Duct Fitting Loss Calculator - C-Factor Pressure Sizing
Compute aerodynamic dynamic pressure drops (ΔP = C·Pv), ASHRAE local loss coefficients, and equivalent straight duct lengths across elbows and transitions.
Duct Silencer Insertion Loss & Noise Reduction Calculator
Compute octave-band acoustic insertion loss (dB), airflow pressure drop, and regenerated aerodynamic self-noise for dissipative rectangular splitters.
Dust Collection Duct Velocity Calculator - ACFM Pipe Size
Determine required particulate conveying transport velocity (FPM), round duct diameter (inches), actual flow velocity, and velocity pressure according to ACGIH standards.
DVL Dead Reckoning Navigation Error Calculator
Subsea Navigation & Inertial Odometry: Model 4-beam Janus Doppler shifts, acoustic sound speed calibration sensitivities, and accumulated Circular Error Probable (CEP) position drift.
Dwight Anode Resistance Calculator - Groundbed Ohm Sizing
Determine electrical grounding resistance (R_a) for single and multiple vertical, horizontal, and slender stand-off anodes per H.B. Dwight and Sunde.
Dynamic Binding Capacity Calculator - Breakthrough Curve DBC
Determine chromatography resin dynamic binding capacity at 5% and 10% breakthrough (DBC10%), residence time, and purification productivity.
ECD Calculator - Equivalent Circulating Density Annular
Compute Annular Pressure Loss (ΔP_ann), dynamic ECD (ppg), and Bottomhole Circulating Pressure (BHCP) to prevent kick influx or formation fracture.
ECM Radar Jamming Burn-Through Calculator
Electronic Warfare & Countermeasures: Compute the Burn-Through Crossover Range ($R_{\text{BT}}$) where radar target echo power overcomes airborne self-screening jamming noise.
ECMO Membrane Oxygenator Gas Transfer Calculator
Extracorporeal life support & cardiopulmonary bypass: Determine oxygen uptake ($V_{O2}$), carbon dioxide elimination ($V_{CO2}$), and sweep gas flow requirements for polymethylpentene ($PMP$) hollow-fiber oxygenators.
Eddington Luminosity Limit Calculator
High-energy astrophysics: Calculate maximum stable radiation luminosity ($L_{\text{Edd}}$), radiation pressure outward acceleration vs gravity, Eddington mass accretion rate ($\dot{M}_{\text{Edd}}$), and Eddington ratio ($\lambda_{\text{Edd}}$).
EDFA Fiber Optical Amplifier Gain Calculator
Optical Amplification Physics: Calculate small-signal and saturated gain ($G$), amplified spontaneous emission ($P_{ASE}$), and Noise Figure ($NF$).
EDFA Optical Amplifier ASE Noise Calculator
DWDM & optical communications: Compute Erbium-Doped Fiber Amplifier (EDFA) saturated gain, amplified spontaneous emission (ASE) noise power, Optical Signal-to-Noise Ratio (OSNR), and noise figure.
EGS Thermal Drawdown Lifetime Calculator
Enhanced Geothermal Systems (EGS): Model fracture heat depletion, thermal breakthrough time ($t_{bt}$), and production temperature decline.
Electric Heat Tracing Calculator - Pipe Wattage Sizing
Calculate pipe heat loss wattage (W/ft & W/m), select self-regulating cable rating, account for valve allowances, and size electrical breaker amperage.
Electric Propulsion Power Sizing Calculator
Space Mission Systems Engineering: Balance delta-V ($\Delta V$), specific impulse ($I_{sp}$), solar/nuclear power mass, and continuous thrust burn duration.
Electrodialysis Reversal Limiting Current Calculator
Compute limiting current density ($i_{lim}/C$), Cowan resistance inflection point, salt flux, and specific electrical energy consumption per $m^3$ treated.
Electroless Nickel Deposition Calculator
Autocatalytic Surface Finishing: Compute plating speed, cycle time, tank loading ratio ($A/V$), and hypophosphite replenishment per ISO 4527.
Electroosmotic Flow Velocity Calculator
Microfluidic Electrokinetics: Determine electroosmotic slip velocity ($u_{EOF}$), Debye length ($\lambda_D$), mobility ($\mu_{EOF}$), and volumetric flow rate.
Electrophoretic Mobility & Gel Calculator
Bioanalytical engineering & molecular separation: Compute electrophoretic mobility ($\mu_e$), DNA/protein migration velocity, Ferguson plot retardation, and Joule heating dissipation.
Electroplating Faraday Thickness Calculator
Electrochemical Surface Finishing: Determine metal coating thickness, plating duration, mass deposited, and electrical energy via Faraday's law of electrolysis.
Electrostatic Precipitator Calculator - Deutsch Anderson
Model particulate capture efficiency, effective electrical migration velocity (w_e), and required Specific Collection Area (SCA) via the classical Deutsch-Anderson equation.
Electrostatic Precipitator Efficiency Calculator - Deutsch
Calculate industrial electrostatic precipitator collection efficiency, required Specific Collection Area (SCA), plate surface area, and migration velocity.
Electrowetting EWOD Contact Angle Calculator
Digital microfluidics & lab-on-a-chip: Calculate voltage-induced droplet contact angle reduction ($\theta(V)$), Lippmann-Young electrowetting number ($\eta$), and lateral actuation force ($f_{act}$).
EMC Shielding Effectiveness Calculator
Electromagnetic Compatibility: Compute total shielding attenuation ($SE = R + A + B$), skin depth ($\delta$), and near- vs far-field reflection losses per Schelkunoff.
Emulsion Droplet Size Calculator - Weber Sauter Mean D32
Estimate equilibrium Sauter mean droplet diameter (d32) in turbulent stirred dispersions using Hinze-Kolmogorov theory and Calabrese correlations.
Emulsion Inversion Viscosity Calculator
Flow Assurance Hydraulics: Determine effective emulsion viscosity across water cut profiles, peak viscosity at the phase inversion point, and pumping power penalties.
Enclosure Aperture RF Leakage Calculator
Chassis Shielding Engineering: Predict aperture slot and perforated ventilation array RF leakage attenuation and waveguide-below-cutoff effects per IEEE 299.
Engine Flywheel Fluctuation Sizing Calculator
Reciprocating engines & compressors: Calculate required flywheel mass moment of inertia ($I$), rim dimensions, coefficient of speed fluctuation ($C_f$), and rim centrifugal hoop stress ($\sigma_{hoop}$).
EPB TBM Face Support Pressure Calculator
Mechanized Soft Ground Tunneling: Determine required EPB muck chamber support pressure to prevent face collapse and surface blowouts.
Equivalent Single Axle Load ESAL Calculator
Highway traffic analysis & transportation engineering: Calculate cumulative 18-kip Equivalent Single Axle Loads (ESALs) over pavement design life factoring compound traffic growth and vehicle class truck factors.
Ergun Packed Bed Pressure Drop Calculator
Chemical reactor engineering & filtration: Calculate total pressure drop ($\Delta P$), Blake-Kozeny laminar and Burke-Plummer turbulent components, modified friction factor ($f_p$), and minimum fluidization velocity ($u_{mf}$).
ESP Pump Sizing Calculator - Electrical Submersible Head
Determine Total Dynamic Head (TDH), number of centrifugal impeller stages, and electric motor nameplate horsepower (HP) for artificial lift ESP installations.
Euler Turbomachinery Equation Work Calculator
Compute angular momentum transfer, impeller tip velocity ($U_2$), slip factor ($\sigma$), theoretical dynamic head ($H_{th}$), and shaft power output.
Eurocode 3 Steel Fire Resistance Calculator
Structural Fire Engineering: Determine temperature-dependent reduction factors $k_{y,\theta}$, $k_{E,\theta}$, effective yield strength $f_{y,\theta}$, and critical failure temperature per EN 1993-1-2.
EUV Lithography Photon Shot Noise Calculator
Extreme ultraviolet lithography & nanometer patterning: Model stochastic photon shot noise, Poisson photon count variance, line edge roughness (LER), and contact hole yield.
Evaporative Condenser Calculator - Ammonia Heat Rejection
Determine Total Heat of Rejection (THR), nominal model selection rating, water spray recirculation flow (GPM), and airflow CFM for ammonia (R-717) and halocarbon condensers.
Evaporative Condenser Heat Rejection Calculator
Compute Total Heat Rejection ($THR$), approach to ambient wet-bulb temperature, water evaporation rate, drift loss, blowdown, and required freshwater makeup flow.
Evaporative Condenser Water Calculator - Makeup Sizing
Determine evaporation, blowdown, and drift loss rates to calculate total fresh makeup water consumption (GPM and gal/day) for industrial refrigeration condensers.