Engineering Calculators & Calculation Tools

What Are the Best Free Unit Converters for Engineers?

Unit conversions consume time you'd rather spend on actual engineering. Converting PSI to MPa, inches to millimeters, BTU to joules, horsepower to watts, gallons per minute to liters per second. You might do five conversions before lunch on some days. Manually calculating each one wastes time and introduces arithmetic errors, especially when you're switching between imperial and metric repeatedly or dealing with compound units like pound-force per square inch to megapascals.

UnitConverters.net handles most engineering unit conversions with instant results as you type. Clean interface, no ads blocking the conversion fields, covers length, mass, temperature, pressure, energy, power, torque, flow rate, viscosity. Type "1000 psi" and immediately see "6.895 MPa" without clicking through multiple menus. Bookmark it and use the same converter every time instead of googling "psi to mpa converter" repeatedly.

ConvertUnits.com excels at engineering-specific units that general converters miss: stress (psi, ksi, MPa, GPa), moment of inertia (in⁴, mm⁴), section modulus, thermal conductivity (BTU·in/(hr·ft²·°F) to W/(m·K)), viscosity (centipoise to Pa·s). If you're doing stress analysis, thermal design, or fluid mechanics calculations where units get messy, ConvertUnits handles the obscure stuff.

OnlineConversion.com provides detailed conversion tables showing multiple equivalent values simultaneously. Instead of converting one value at a time, you see a table: 100 psi = 689.5 kPa = 6.895 bar = 0.6895 MPa = 6.804 atm. Useful when you're working with international teams and need to communicate values in multiple unit systems.

Pick one converter, bookmark it, build the habit of using it every single time you need a conversion. The goal isn't collecting different conversion websites, it's eliminating manual unit conversion from your workflow entirely. Twenty minutes spent converting units by hand is twenty minutes wasted. These tools are free, instant, and accurate. Use them so you can focus on actual engineering problems instead of arithmetic. Review our engineering math fundamentals to strengthen your unit analysis skills.

Where Can I Find Free Beam Deflection Calculators?

Quick beam checks come up constantly in mechanical design work. You need to know if that cantilevered bracket will hold 500 pounds before you finalize the mounting details. Whether that shelf will deflect more than the 0.1 inch your design allows under distributed load. How much stress develops in a simply supported beam with a point load at midspan. Running full FEA simulation software is overkill for simple beam problems. Free online beam calculators give you bending moments, shear forces, deflections, and stress values in seconds for common loading scenarios.

WebStructural lets you throw in beam dimensions, pick how it's supported (pinned ends, cantilevered, whatever), drop some loads on it, and watch the moment diagram update while you're still typing. The interface is clean enough that you're not hunting for buttons. Material properties, cross section, loading configuration all feed into live calculations showing maximum stress, deflection at any point, and reaction forces. No downloading software that takes twenty minutes to open or creating yet another account. Just model the beam and get your numbers.

SkyCiv Beam Calculator handles more complex loading including multiple point loads, distributed loads, moments, and mixed boundary conditions on a single beam. Free tier lets you analyze standard beam configurations. The visual diagrams help verify your loading assumptions match what you intended. Especially useful when you're checking homework problems or validating hand calculations before submitting design documentation.

Calcs.com free calculators includes beam analysis plus bolt group analysis and moment of inertia calculations for custom cross sections. The calculation reports show detailed step-by-step work, which helps if you're learning beam theory or need to include calculation backup in reports. Results include maximum bending stress, shear stress, deflection, and all reaction forces.

Use these for early design checks, homework verification, and confirming hand calculations, not for final design decisions on critical structures. The calculators compute exactly what you tell them to, even if your boundary conditions don't match the real situation. How you support the beam matters enormously. Your loading assumptions matter. Material properties matter. Learn beam theory from fundamentals first so you understand what you're calculating, then use calculators to speed up the math after you've set up the problem correctly.

Which Free Material Databases Can I Use Right Now?

Material datasheets disappear when you need them most. Textbook property tables cover maybe ten common alloys plus a handful of generic plastics. Suppliers list trade names but hide actual mechanical properties behind sales representatives. You need real numbers: yield strength, ultimate tensile strength, elastic modulus, thermal conductivity, density, coefficient of thermal expansion for materials you might actually spec in a design. Material property databases let you search thousands of materials with verified engineering properties faster than hunting through manufacturer PDF archives or calling suppliers.

MatWeb is the industry standard free material database covering over 150,000 materials: metals (steels, aluminum alloys, titanium, copper alloys, specialty alloys), polymers (ABS, polycarbonate, nylon, PEEK, acetal), ceramics (alumina, silicon carbide, glass), and composites (carbon fiber, fiberglass). Search by material name, manufacturer, property values, or tradename. Each entry shows mechanical properties (yield, tensile, modulus, elongation), physical properties (density, melting point), and thermal properties (conductivity, expansion coefficient, specific heat).

Engineering Toolbox materials section provides quick reference tables for common engineering materials organized by category. Good for initial selection when you need ballpark properties fast: "I need a plastic stronger than ABS" or "What's the thermal conductivity of aluminum versus copper?" The data is less comprehensive than MatWeb but easier to browse when you're not sure exactly what material you're looking for yet.

AZoM material database focuses on detailed technical articles explaining material properties, processing methods, and typical applications alongside property data. Useful when you're learning about a new material class or trying to understand why one alloy costs 3x more than another despite similar strength values. The articles provide context that raw property tables don't.

Use online databases for material comparison and initial selection, but always verify final properties with actual supplier datasheets before releasing designs. Material properties vary based on specific grade, processing method, heat treatment, and lot-to-lot variation. MatWeb shows typical values for 6061-T6 aluminum, but your supplier's actual material might vary ±5%. For critical applications, get certified test data from your material supplier showing the exact properties of the specific lot you're buying. Databases give you starting points. Suppliers give you guaranteed values.

What Are the Best Steam Table and Fluid Property Calculators?

Thermodynamic and fluid property lookups slow down every thermal system calculation. Steam enthalpy at 150 psi and 400°F from printed tables requires interpolating between table values by hand. Refrigerant R-134a properties at specific temperatures and pressures means flipping through multiple pages looking for the right chart. Air density and viscosity at altitude for aerodynamic drag calculations involves assumptions and approximations from limited tabulated data. Online calculators eliminate interpolation errors and give you exact values at any operating condition instantly instead of spending ten minutes per lookup.

NIST WebBook thermophysical properties database is the authoritative source maintained by the National Institute of Standards and Technology. Search for any pure fluid (water, steam, air, nitrogen, carbon dioxide, ammonia, dozens of refrigerants) and get precise properties: enthalpy, entropy, specific volume, viscosity, thermal conductivity, Prandtl number at whatever temperature and pressure you specify. The data comes from government standards, so you can trust it for professional calculations and academic work. Referenced in peer-reviewed papers and industry standards worldwide.

TLV Steam Tables Calculator focuses specifically on steam and condensate properties for HVAC and process equipment design. Enter temperature or pressure and immediately get saturated or superheated steam enthalpy, specific volume, viscosity, and quality. Especially useful for sizing steam traps, calculating condensate loads, determining pipe sizes for steam distribution, and verifying boiler efficiency. Interface designed for mechanical engineers doing thermal calculations, not academics.

Engineering Toolbox fluid mechanics calculators handle practical problems: pipe friction pressure drop using Darcy-Weisbach equation, Reynolds number for determining laminar versus turbulent flow, pump head calculations, orifice flow rates, duct sizing for air handling systems. Good for quick calculations when you remember the equation but don't want to look up friction factors or fluid properties manually.

These tools matter most if you work in HVAC design, thermal systems, or fluid mechanics. Bookmark NIST WebBook for precise thermophysical properties when accuracy matters for design verification or academic work. Use TLV for fast steam calculations during equipment selection. Engineering Toolbox works well for initial sizing and feasibility checks. All three are free and faster than flipping through printed property tables while introducing fewer transcription errors.

Where Can I Find Bolt Torque and Mechanical Design Calculators?

Mechanical design calculations follow standard formulas but involve tedious arithmetic that consumes time better spent on actual design decisions. Bolt installation torque based on thread size, material grade, and lubrication condition. Spring rate for compression springs given wire diameter, coil diameter, number of coils, and material modulus. Gear tooth geometry including pitch diameter, base circle, and involute profile. Shaft sizing for combined bending and torsion loading. Belt drive selection matching motor horsepower to driven equipment. Tolerance stack analysis for assemblies with multiple components. Free online calculators handle the repetitive math so you can focus on whether your design actually works.

Engineers Edge calculators provides an extensive collection covering most mechanical design calculations: bolt and fastener sizing, spring design (compression, extension, torsion), gear design (spur, helical, bevel), shaft analysis for combined loading, bearing selection, tolerance analysis, stress concentration factors, pressure vessel calculations. Each calculator includes the relevant equations and assumptions so you understand what it's computing. Good reference when you remember the general approach but don't want to look up constants or coefficients.

MechaniCalc offers free mechanical engineering calculators with detailed documentation explaining the theory behind each calculation. Bolted joint analysis shows preload, clamping force, factor of safety against yielding and fatigue. Shaft design calculations include deflection, critical speed, and combined stress from bending plus torsion. Spring calculators verify solid height, free length, stress, and deflection. The step-by-step documentation helps if you're learning machine design or need to explain your calculations in design reports.

Bolt torque calculators specifically handle installation torque specifications based on fastener size (M6, 1/4-20, etc.), material grade (8.8 metric, Grade 5 or Grade 8 SAE), and lubrication condition (dry assembly, anti-seize, oil lubricated). Critical for preventing overtightening that strips threads or undertightening that allows joints to loosen. The calculators include torque-tension relationships accounting for thread friction and under-head friction based on standard coefficients.

Use these tools for initial sizing and design concept verification, not as substitutes for understanding machine design fundamentals. They work great for standard mechanical components following published design methods. For unusual loading conditions, custom geometries, or critical safety applications, verify calculator results with handbook calculations, detailed FEA analysis, or physical testing. These calculators assume you understand what you're calculating and why. Bad inputs produce bad outputs even when the math is correct. Learn fundamentals first from textbooks and engineering fundamentals, then use calculators to eliminate arithmetic drudgery from your workflow.

Using Calculators Without Replacing Engineering Judgment

These calculators work for professional engineering work, university coursework, technical training, and personal projects. Use them to verify your hand calculations before submitting work reports. Check homework problems before turning in assignments. Validate designs for home workshop projects or DIY builds. But remember: calculators save time, they don't replace understanding. A beam calculator gives you deflection numbers, but it doesn't tell you if your support conditions match the real situation. A material database shows properties, but it doesn't explain why your prototype cracked.

Treat these tools as math helpers, not design authorities. Learn the principles from Fundamentals, understand the theory behind the calculations, then use tools to speed up the number work. Always check if results make sense. If a beam deflection seems wrong, it probably is. Either you entered something incorrectly or you need to review the concept. Calculators multiply both good engineering judgment and bad assumptions. Make sure you're multiplying the right one.