multicalci.com
Standards-based Engineering Calculators & Reference Tools · Free · Browser-based · No login
29
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8
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SI+US
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📐 SI & Imperial
✅ Free Always
⭐ Most-used calculators & reference tools
⚗️Process & Fluid Systems15 tools
🎯Orifice Design & Sizing→
ISO 5167-2 orifice plate: Reader-Harris/Gallagher discharge coefficient, beta ratio, DP & permanent pressure loss.
ISO 5167RH/G CdDP Meter
🌀Pump, Compressor & Fan→
Centrifugal & PD pumps (NPSHA/NPSHR, affinity laws), multi-stage compressors with intercoolers, fans & blowers — isentropic & polytropic.
Pump/NPSHCompressorFan/BlowerAffinity Laws
🧪Gas Equation of State→
Real gas behaviour using Peng-Robinson, Soave-Redlich-Kwong & van der Waals EOS. Z-factor & compressibility calculations.
Peng-RobinsonSRKZ-Factor
🔄Engineering Units Converter→
30+ categories: pressure, flow, temperature, energy, power, viscosity, force & more. Full SI ↔ Imperial conversion.
SI ↔ Imperial30+ Categories
📉Pipe Pressure Drop Calculator→
Darcy-Weisbach & Hazen-Williams pipe friction losses. Colebrook-White friction factor, fittings, elevation head & multi-segment networks.
Darcy-WeisbachColebrook-WhiteFittings
🔧NPSH Calculator→
Net Positive Suction Head Available vs Required. Cavitation risk assessment, vapour pressure correction, suction line losses & pump selection guidance.
NPSHACavitationSuction Head
📐Head & Pressure Calculator→
Static, dynamic & total head calculations. Pump head, system curve, fluid column pressure for any fluid density & elevation difference.
Static HeadSystem CurvePump Head
🎛️Control Valve Sizing→
IEC 60534 Cv/Kv sizing for liquids, gases & steam. Choked flow, cavitation index, inherent characteristics & noise prediction.
IEC 60534Cv/KvChoked Flow
🛡️PSV / Relief Valve Sizing→
Gas/vapor, steam, liquid, fire case (wetted & unwetted) & two-phase omega method sizing with automatic API 526 letter-orifice selection D–T.
API 520API 521API 526
💨Pipe Velocity & Sizing Calculator→
Flow velocity from flow rate & pipe ID, or recommended inside diameter & nearest NPS size from flow rate & target velocity.
Flow VelocityNPS Sizing
🧊Pipe Volume Calculator→
Internal volume & liquid fill capacity from pipe ID & length, or NPS & schedule. Litres, US gallons, m³, barrels & liquid weight.
NPS/ScheduleFill Capacity
⚖️Pipe Weight Calculator→
Pipe weight per foot/metre & total weight from NPS & schedule or custom OD/wall thickness. ASME B36.10 / B36.19 dimensions.
ASME B36.10Steel Weight
🔩Flange Rating Calculator→
ASME B16.5 pressure-temperature class lookup. Select flange class & material group, enter design temperature for interpolated allowable pressure.
ASME B16.5Class 150–2500
⚙️Pump Power Calculator→
Hydraulic power, brake (shaft) power & motor input power from flow rate, head, specific gravity & pump/motor efficiency.
Hydraulic PowerkW/hp
⚖️ Material & Energy BalanceBeta →
Flowsheet mass & energy balances: mixer, splitter, flash drum, heat exchanger, pump/compressor/turbine & conversion reactor. NIST-based enthalpies on a formation basis, IAPWS-IF97 steam, chainable units.
Mass & Energy 6 Unit Ops NIST Basis Beta
🌡️Heat Transfer & Thermodynamics9 tools
♨️Heat Exchanger Design→
Shell & tube (TEMA classifications), Bell-Delaware shell-side, LMTD correction factor, overall U-value & fouling resistance.
TEMABell-DelawareLMTD
🌡️LMTD Calculator→
Log mean temperature difference for counter-current or co-current heat exchangers, with optional correction factor F for multi-pass units.
Counter/Co-currentCorrection Factor F
💨Steam Properties (IAPWS-IF97)→
Full steam tables per IAPWS-IF97. Saturated & superheated steam properties, wet quality, enthalpy, entropy & specific volume.
IAPWS-IF97SaturationSuperheat
⚡Steam Turbine Power→
Isentropic efficiency, power output & steam consumption for condensing & back-pressure turbines. Rankine cycle analysis.
IsentropicRankine CycleBack-Pressure
❄️Steam Quench Calculator→
Desuperheater & steam quench calculations. Spray water flow rate, outlet temperature & enthalpy balance for steam conditioning.
DesuperheaterSpray WaterEnthalpy
🔁Rankine Cycle Calculator→
Ideal & actual Rankine cycle analysis. Thermal efficiency, boiler heat input, turbine & pump work, condenser heat rejection.
Thermal EfficiencyBoilerCondenser
🌬️Psychrometric Calculator→
Moist air: dew point, wet-bulb, humidity ratio, specific enthalpy & volume for HVAC & drying system design.
Dew PointWet BulbHVAC
🏭Cooling Tower Performance→
CTI ATC-105 thermal performance: NTU-Merkel method, approach & range, tower characteristic, drift & evaporation losses.
CTI ATC-105NTU-MerkelApproach/Range
🧊Insulation Heat Loss Calculator→
Heat loss & jacket surface temperature for insulated pipes, tanks, spheres & buried lines. Multi-layer, temperature-dependent conductivity, condensation & burn-risk checks.
Multi-LayerCondensation CheckBurn Risk
🛢️Vessels, Separators & Materials5 tools
🛢️Tank Volume Calculator→
Horizontal & vertical tanks with flat, hemispherical, 2:1 ellipsoidal, torispherical (ASME F&D) or conical heads. Partial-fill volume at any level, liquid mass & downloadable dip chart in m³, litres & US gallons.
ASME F&DDip ChartPartial Fill
🛢️Vessel / Separator Sizing→
Horizontal & vertical separators: retention time, mist eliminator, nozzle sizing per ASME VIII & API 12J.
ASME VIIIAPI 12JSeparator
🔬Material of Construction→
Corrosion resistance guide for pipes & equipment. Select optimal material by fluid chemistry, temperature & concentration.
Corrosion GuideAlloysPiping
📚Material Grades Library→
Comprehensive material grades reference: ASTM, DIN, EN & ISO standards for steels, alloys & non-ferrous materials.
ASTMDIN/ENSteel Grades
💧Water Treatment Calculator→
Chemical dosing, blowdown rates, cycles of concentration for boiler & cooling tower water treatment systems.
Chemical DosingBlowdownBoiler Water
📋 Engineering Standards & Codes 5 tools
📋 Engineering Standards & Codes Finder →
Instantly look up applicable codes for any equipment — pumps, vessels, valves, piping, tanks, heat exchangers, instruments & more. Covers API, ASME, ASTM, ISO, EN, DIN, BS, JIS and Indian Standards (IS, IBR) with latest edition, scope, key requirements & related standards.
API ASME ISO IS / IBR 200+ Standards New
🔷 P&ID Symbol Finder →
Search 368+ P&ID symbols instantly by substring — pumps, valves, heat exchangers, vessels, instruments & process lines. Based on ANSI/ISA-5.1 & ISO 10628 standards, with a searchable instrument tag abbreviations panel. Export as PNG, JPG or SVG.
ANSI/ISA-5.1 ISO 10628 368+ Symbols New
📚 Material Grades Library →
Cross-reference ASTM, DIN, EN, ISO & IS material designations for steels, stainless, alloy and non-ferrous materials used in process plant design.
ASTM DIN / EN BIS / IS Cross-reference
🔬 Material of Construction Guide →
Select the right material for pipes & equipment based on fluid chemistry, temperature and corrosion resistance data. Practical reference for alloy screening in process plant specifications.
Corrosion Guide Alloy Selection Reference
💰 BOQ Capital Cost EstimatorBeta →
Bill of quantities capital cost estimator with 1,400+ line items across pumps, vessels, cabling, concrete, earthwork, piping & valves. Tiered ±30/20/10% accuracy across 8 regions.
1,400+ Line Items 8 Regions Beta
Engineering suites
🏗️CivilCalc Pro→
Beam bending, column, concrete mix, pipe flow (Manning/H-W), retaining wall, earthwork & surveying.
StructuralHydraulicsGeotechnical
⚡ElecCalc Pro→
Ohm's law, AC/DC power, cable sizing (IEC 60228), motor, transformer, fault current (IEC 60909) & HV testing.
Cable SizingMotorIEC 60909
📡InstruCalc Pro→
4–20 mA signal conversion, square root extractor (DP flow), loop integrity, thermowell (ASME PTC 19.3) & thermocouple reference.
4-20mAThermowellASME PTC 19.3
⚙️MechCalc Pro→
Structural, beam, ASME VIII vessel, bolt & flange, AWS D1.1 weld, AGMA gear, shaft, spring, fastener & CNC machining.
ASME VIIIAWS D1.1AGMA
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Complete Engineering Calculators & Reference Tools Directory

Browse all free engineering calculators and reference tools including process, heat transfer, civil, electrical, mechanical, instrumentation and engineering standards lookup.

Process & Fluid Systems

Heat Transfer & Thermodynamics

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Standards & Reference

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Frequently Asked Questions

Are the calculators free to use?

Yes — all calculators are completely free, run in your browser and require no login, registration or subscription. They work on any device with a modern browser.

Which engineering standards are implemented?

ISO 5167 (orifice/flow), IEC 60534 (control valves), API 520/521/526 (pressure relief valve sizing), IAPWS-IF97 (steam properties), TEMA E/F/G/H/J/X (heat exchangers), ASME B31.3/VIII (piping/vessels), CTI ATC-105 (cooling towers), Darcy-Weisbach + Colebrook-White (pipe flow), ASME PTC 19.3 (thermowell analysis), API 12J (separators), Peng-Robinson & SRK EOS (gas properties). The Standards & Codes Finder covers 200+ standards across API, ASME, ASTM, ISO, EN, DIN, BS and Indian Standards (IS, IBR).

How do I calculate the volume of a partially filled tank?

Use the Tank Volume Calculator. For a horizontal cylinder the shell uses the exact circular-segment formula, and dished head pairs use the spheroidal relation V = π·a·h²·(3R−h)/(3R), where a is the head inside depth — exact for hemispherical and 2:1 ellipsoidal heads. Torispherical (ASME F&D) heads are computed from crown and knuckle geometry. The calculator also generates a level-to-volume dip chart you can download as CSV.

Do calculators support both SI and Imperial units?

Yes. All process and fluid calculators support one-click switching between SI (metric) and US Customary (Imperial) unit systems. Results update instantly without re-entering data.

Can results be used for final engineering designs?

These calculators are suitable for preliminary engineering, feasibility studies, educational use and cross-checking. All results must be independently verified by a qualified registered engineer against applicable codes and standards before use in final designs.

What does the Standards & Codes Finder cover?

The Engineering Standards & Codes Finder covers 200+ standards including API, ASME, ASTM, ISO, EN, DIN, BS, JIS and Indian Standards (IS, IBR). Search by equipment type — pumps, valves, vessels, piping, heat exchangers, storage tanks, instruments, rotating machinery and more — to instantly see applicable codes, latest edition, scope, key technical requirements and related standards.