AnythingOnline / Free calculators and utilities

Engineering & Science calculators

Choose a task below. Check each calculator’s assumptions and units before using its result.

CSTR Space Time and Conversion Calculator - Kinetics

Calculate continuous stirred tank reactor space time (τ), Damköhler number (Da), fractional conversion (X), and required vessel volume.

Cunningham Slip Correction Factor Calculator

Aerosol mechanics & fluid dynamics: Calculate the Knudsen number ($Kn$), Cunningham slip correction factor ($C_c$), corrected Stokes drag force ($F_d$), and terminal gravitational settling velocity ($v_{ts}$).

CWR Rail Buckling Calculator - AREMA Thermal Stress Sizing

Calculate longitudinal thermal stresses, rail neutral temperature deviations, ballast lateral resistance, and track buckling ("sun kink") safety per AREMA Chapter 5.

CWR Rail Thermal Buckling Calculator

Railway civil engineering: Model Continuous Welded Rail (CWR) longitudinal thermal expansion force ($P_{therm}$), lateral ballast resistance, critical buckling load ($P_{cr}$), and allowable rail temperature rise.

Cycles of Concentration Calculator - Water Conductivity

Determine actual operating Cycles of Concentration (COC) using electrical conductivity or TDS, identify mineral scaling caps, and calculate water savings.

Cyclone Separator Calculator - D50 Cut Point Efficiency

Determine aerodynamic cut-point particle diameter (d50 in microns), overall collection efficiency, inlet velocity, and static pressure drop for cyclone pre-cleaners.

Cyclone Separator Cut Point Calculator - Pressure Drop

Calculate Stairmand and Lapple cyclone cut diameter (d50), pressure drop, inlet velocity, and particle collection efficiency curves.

Cyclone Separator Cut Size d50 Calculator

Industrial gas cleaning & dust collection: Model standard Stairmand high-efficiency cyclones, calculating centrifugal cut size ($d_{50}$), overall collection efficiency, and Euler pressure drop ($\Delta P$).

DAF Air-to-Solids Ratio & Saturator Calculator

Determine Air-to-Solids ($A/S$) ratio, saturator vessel operating pressure, recycle stream pumping rate, and hydraulic surface rise rate for industrial DAF clarifiers.

Datum Shift & Virtual Condition Calculator

Compute Virtual Condition ($VC$), Resultant Condition ($RC$), Maximum Material Boundary (MMB), and available datum shift / rocking allowance per ASME Y14.5.

DC SQUID Magnetic Flux Noise Calculator

Quantum magnetometry: Model DC Superconducting Quantum Interference Devices (SQUIDs), magnetic flux quantum modulation ($Phi_0$), flux-to-voltage transfer gain ($V_\Phi$), and thermal Nyquist flux noise ($S_\Phi^{1/2}$).

DDT Detonation Run-Up Distance Calculator

Explosion dynamics & supersonic combustion: Compute the Chapman-Jouguet ($CJ$) detonation velocity ($D_{CJ}$), peak detonation shock pressure ($P_{CJ}$), and Deflagration-to-Detonation Transition ($DDT$) run-up distance.

De Laval Supersonic Nozzle Flow Calculator

Compute sonic throat conditions ($M=1$), choked mass flow rate ($\dot{m}$), exit Mach number ($M_e$), expansion area ratio ($A_e/A^*$), and ideal thrust.

Deal-Grove Silicon Thermal Oxidation Calculator

Semiconductor device physics & wafer processing: Model thermal silicon dioxide ($SiO_2$) growth kinetics, linear and parabolic rate regimes, and consumed silicon thickness.

Deep Space Laser Downlink Data Rate Calculator

Interplanetary Optical Telemetry: Compute supportable downlink data rates ($R_b$), received photon arrival rates, and communication performance from Mars and outer planetary probes.

Delayed Coker Yield & Drum Cycle Calculator

Calculate product yields (Coke, LCGO, HCGO, Naphtha, Off-Gas) via Gary-Handwerk correlations, coke drum capacity, outage height, and 16-24 hr decoking cycle timing.

Den Hartog Transmission Galloping Calculator

Power Line Aeroelastics: Evaluate the Den Hartog stability criterion ($dC_L/d\alpha + C_D < 0$) and predict galloping onset wind speed ($V_g$).

Denavit-Hartenberg Transformation Matrix Calculator

Robotics kinematics & multibody mechanics: Compute the $4 imes 4$ homogeneous transformation matrix ($^{i-1}T_i$) from standard Denavit-Hartenberg (D-H) parameters ($a_i, alpha_i, d_i, heta_i$).

Dense Medium Separation Ep Calculator

Mineral processing & coal beneficiation: Calculate cut point density (ρ₅₀), Ecart Probable Moyen (Ep), imperfection index, and Tromp partition sharpness.

Dense Phase Pneumatic Calculator - Slug Flow Pressure

Calculate dense-phase pneumatic conveying slug flow pressure drop, mass phase ratio, low superficial velocity, and pressure vessel transporter volume.

Deoiling Hydrocyclone Calculator - Split Ratio Sizing

Size produced water liquid-liquid deoiling hydrocyclones, determine reject overflow split ratio (1-3%), and estimate D50 cut size.

Departure from Nucleate Boiling DNBR Calculator

Nuclear Thermal Hydraulics & Safety: Calculate local Critical Heat Flux ($q^{\prime\prime}_{\text{crit}}$), Departure from Nucleate Boiling Ratio ($\text{DNBR}$), Tong W-3 correlation, and safety limits.

Departure from Nucleate Boiling Ratio W-3 Calculator

Determine critical heat flux (CHF) via Tong W-3 correlation, actual local heat flux, and DNB thermal-hydraulic design safety margin.

Desiccant Wheel Dehumidifier Calculator - Moisture Rate

Calculate rotary desiccant wheel moisture extraction rates (grains/lb and GPH), process air discharge temperature, and reactivation heater thermal energy.

Die Per Wafer & Murphy Yield Calculator

Semiconductor fab economics & defect metrology: Compute gross die per wafer (DPW), defect-limited chip yield (Murphy, Seeds, and Poisson models), and net good die.

Die Swell Extrusion Barus Ratio Calculator

Polymer processing & die tooling design: Calculate the extrudate swell ratio ($B = D_e / D_0$) from wall shear stress ($\tau_w$), first normal stress difference ($N_1$), and die aspect ratio ($L/D$).

Dielectrophoresis Force Calculator

AC electrokinetics & BioMEMS: Calculate time-averaged dielectrophoretic force (\(F_{\text{DEP}}\)), Clausius-Mossotti factor (\(f_{\text{CM}}\)), and crossover frequency (\(f_{xo}\)).

Diffraction Grating Resolving Power Calculator

Determine diffraction grating resolving power ($R = \lambda / \Delta\lambda$), angular dispersion ($d\beta/d\lambda$), diffraction angle ($\beta$), and Rayleigh resolution limit.

Dilution Refrigerator Power Calculator

Quantum Computing Cryogenics: Calculate $^3\text{He}-^4\text{He}$ dilution mixing chamber cooling power ($\dot{Q}$), molar circulation rate ($\dot{n}_3$), and base temperature ($T_{base}$).

Direct Air Capture TSA Sorbent Energy Calculator

Atmospheric Carbon Removal: Model Temperature Vacuum Swing Adsorption (TVSA), contactor air-side pressure drops, and electrical/thermal energy per metric ton of ambient $CO_2$ captured.

Direct Electrical Heating Calculator - Subsea Flowline DEH

Model single-phase 50/60 Hz AC power delivery, current division between pipeline and seawater, and active heating duty (W/m) to prevent hydrate plugs.

Disc Stack Centrifuge Calculator - Sigma Factor G-Force

Calculate equivalent clarifying area (Ambler Sigma factor Σ), bowl G-force, Stokes particle cut-off diameter, and maximum volumetric throughput for industrial disc stack separators.

Distillation Column Reflux Ratio Calculator - Underwood

Calculate Fenske minimum theoretical stages, Underwood minimum reflux ratio (Rmin), Gilliland operating stages, and column boilup requirements.

Distillation Condenser Duty Calculator - Reflux Subcooling

Calculate total condensing and sensible subcooling heat duty, cooling water circulation rate, and the cold reflux internal reflux ratio amplification.

Distillation Flooding Calculator - Fair Correlation Sizing

Calculate tray jet flooding vapor velocity (u_flood), Fair capacity factor (CSB), Flow Parameter (FLV), and allowable operational percentage of flood per Fair correlation.

Distillation Tray Flooding Velocity Calculator - Sieve

Calculate Souders-Brown sieve tray vapor flooding velocity, operating percent flood, Fair weep limit, and hydrodynamic operating envelope.

Distillers Mash Strike Water Calculator - Grain Grist

Model thermal equilibrium strike water temperatures, grain heat capacity, liquor-to-grist ratios, and enzyme conversion rests for bourbon, rye, and single malt mashing.

Distributed Bragg Reflector Bandgap Calculator

Nanophotonics & laser mirror design: Compute quarter-wave optical layer thicknesses ($d_1, d_2$), stopband spectral width ($\Delta\lambda$), maximum power reflectance ($R_{max}$), and optical penetration depth ($L_{pen}$).

DNV RP B401 Cathodic Protection Calculator - Offshore CP

Calculate initial, mean, and final cathodic protection current demand (Amps) and total net galvanic anode mass (kg) per DNV-RP-B401 standards.

Doppler Radar Blind Speed PRF Calculator

Radar Signal Processing: Balance the radar dilemma between maximum unambiguous range ($R_{ua}$) and first blind velocity ($v_{b1}$).

Double Pipe Heat Exchanger Calculator - Annulus Drop

Model hairpin double-pipe heat exchangers: calculate annular hydraulic and equivalent diameters, Dittus-Boelter heat transfer coefficients, and annular pressure drop.

Double-Layer V-Coat AR Coating Calculator

Precision Optical Thin Films: Design double-layer antireflective coatings ($V$-coat) achieving zero residual reflectance ($R = 0$) at single laser wavelengths.

Downcomer Backup Calculator - Distillation Choke Flood

Calculate total clear liquid backup in downcomers (hdc), froth density aeration, head loss under the apron, and downcomer choke flood percentage.

Draft Tube Pressure Recovery Calculator

Hydraulic Turbines (Francis & Kaplan): Calculate diffuser kinetic energy conversion, suction head, runner exit pressure, and cavitation margin.

Dranchuk-Abou-Kassem Gas Z-Factor Calculator

Natural Gas Thermodynamics: Calculate gas compressibility factor ($Z$), pseudo-reduced properties ($P_{pr}, T_{pr}$), and gas FVF ($B_g$) using the DAK EOS.

Drill Bit Nozzles & Jet Impact Force Calculator

Compute Total Flow Area ($TFA$), nozzle jet velocity ($v_n$), bit pressure drop ($\Delta P_b$), hydraulic horsepower ($HHP$), and bottom-hole cleaning impact force.

Drilled Shaft Axial Capacity Calculator

Deep Foundation Engineering: Estimate ultimate and allowable axial compressive load capacity ($R_{ult}$, $R_{all}$) for drilled shafts / bored piles per FHWA-NHI-10-016.

Drillers vs Wait and Weight Calculator - Kill Simulation

Model and compare peak casing shoe pressures, surface choke profiles, and drillpipe step-down schedules between Driller’s and Wait & Weight methods.