How to Calculate Cycles Per Instruction (CPI Guide)
Understand CPI and IPC in computer architecture. Learn the CPI formula, how to find execution time from instruction count, and a worked example.
Read the GuideEngineering Calculators
Free calculators for common engineering calculations across electrical, mechanical, fluid, machining, manufacturing, computing, and agricultural work, with more tools added as the collection grows. Each one states its formula and assumptions clearly, since engineering conventions vary by discipline and application.
All Engineering Calculators
Solar Battery Calculator
Size your off-grid solar battery bank in amp-hours by entering your daily energy use, system voltage, autonomy days, and depth of discharge.
Open the CalculatorBattery Charge Time Calculator
Calculate how many hours a charger takes to refill a battery from the capacity in Ah, battery voltage, charger power, and charging efficiency.
Open the CalculatorBattery Capacity Calculator
Find how many amp-hours a battery bank needs to support a given load, using voltage and maximum depth of discharge as sizing inputs.
Open the CalculatorUPS Battery Calculator
Find the amp-hours your UPS battery needs using load watts, backup runtime, system voltage, inverter efficiency, and power factor.
Open the CalculatorPulley Calculator
Find the mechanical advantage of any pulley system by entering the load force and effort force. Results in seconds with the formula shown.
Open the CalculatorRMS Calculator
Convert peak AC voltage or current to RMS in one step. This calculator uses the sine-wave formula and explains why RMS matters for AC power measurement.
Open the Calculator3-Phase Power Calculator
Find three-phase apparent and real power in kilowatts by entering line-to-line voltage, line current, and power factor. Formula and example included.
Open the CalculatorBolt Circle Calculator
Find the angle between bolt holes and the chord distance between adjacent holes on any bolt circle. Enter the radius and number of holes for instant results.
Open the CalculatorConduit Size Calculator
Verify conduit fill against National Electrical Code fill limits for 1, 2, or 3+ wires. Enter conduit internal area and total wire area for an instant check.
Open the CalculatorShear Moment Diagram Calculator
Find the support reactions and maximum bending moment for a simply supported beam under a single point load, with the formula and a worked example.
Open the CalculatorSprocket Calculator
Find the drive ratio and output RPM of any sprocket-and-chain system by entering the tooth counts for both sprockets and the input shaft speed.
Open the CalculatorMini-Split Sizing Calculator
Get a rough BTU estimate for a mini split unit by entering your room square footage and selecting your climate zone. See why a Manual J calc may still be needed.
Open the CalculatorTorque Conversion Calculator
Convert torque values between N-m and lb-ft in either direction. Uses the exact SI-to-imperial factor of 0.737562, with the formula and a worked example.
Open the CalculatorCoax Loss Calculator
Find total signal attenuation in dB and the remaining power fraction for a coax cable run. Requires the attenuation factor from the manufacturer's spec sheet.
Open the CalculatorMinimum Circuit Ampacity Calculator
Find the minimum circuit ampacity for a motor branch circuit using the NEC Article 430 formula. Enter the largest motor FLA and other motor FLA totals.
Open the CalculatorAir Change Calculator
Find how many times per hour the air in a room is fully replaced. Enter room dimensions and airflow in CFM to calculate your ACH ventilation rate.
Open the CalculatorBattery Runtime Calculator
Estimate how many hours a battery will run a given load. Enter capacity in Wh or Ah, voltage, system efficiency, and load in watts to find your runtime.
Open the CalculatorPropane Usage Calculator
Estimate propane consumption for any appliance. Enter the BTU/hr rating, daily run hours, and appliance efficiency to find your gallons-per-day usage.
Open the CalculatorWater Softener Size Calculator
Estimate the grain capacity your water softener needs. Enter household water use, hardness in GPG, iron content, and regeneration interval to size your system.
Open the CalculatorWatt Hours to Amp Hours Calculator
Convert battery energy between watt-hours and amp-hours in either direction by entering the energy value and the nominal DC voltage.
Open the CalculatorPipe Weight Calculator
Find steel pipe weight per foot and total weight from outside diameter, wall thickness, and length using the standard plain-end pipe weight formula.
Open the CalculatorVolumetric Flow Rate Calculator
Find volumetric flow rate or fluid velocity in a pipe using the Q = A × v identity from pipe inside diameter and the known value.
Open the CalculatorWatts to Amps Calculator
Convert watts and amps for DC, single-phase AC, and three-phase AC circuits using voltage and, where needed, power factor.
Open the CalculatorTrue Position Calculator
Calculate two-axis GD&T true position from measured X and Y deviations, then compare the diametrical result with a stated tolerance.
Open the CalculatorFriction Loss Calculator
Estimate straight-pipe water head loss with Hazen-Williams using flow, inside diameter, roughness value, and pipe length.
Open the CalculatorSFM Calculator
Calculate machining surface speed, spindle RPM, or cutting diameter from the other two values, with a metres-per-minute result.
Open the CalculatorGPM Calculator
Calculate gallons per minute from a measured volume and time, or use the same basic flow rule to find time or total gallons.
Open the CalculatorGas Spring Calculator
Find a first gas spring force for a hinged lid from its weight and arm lengths, then check the maker's size data before use.
Open the CalculatorGear Ratio Speed Calculator
Find output RPM from a gear ratio or estimate vehicle road speed from engine RPM, tyre diameter, transmission ratio, and final drive.
Open the CalculatorAcres Per Hour Calculator
Estimate effective field capacity from machine width, field speed, and a user-set field efficiency for turns, overlap, and stops.
Open the CalculatorCycles Per Instruction Calculator
Find CPU cycles per instruction, IPC, and optional run time from a cycle count, an instruction count, and the chip clock rate.
Open the CalculatorPlanar Density Calculator
Find atomic planar density from the effective atoms on a crystal plane and the matching two-dimensional area in square nanometres.
Open the CalculatorWhat You Can Work Out With These Engineering Calculators
Engineering calculators handle the conversions and formulas that come up across a wide range of technical disciplines, from electrical power relationships to fluid flow, machining speeds, gear ratios, and computing performance metrics. The underlying math is usually a well-established formula from a specific engineering domain, but applying it correctly depends on using the right convention, units, and assumptions for the task at hand, which is why every tool here states its formula and scope rather than hiding the math behind a single button.
Every tool in this section states its formula, works an example step by step, and is explicit about what the result does and does not cover. These are estimating and educational tools; for safety-critical or code-governed engineering work, always verify results against a professional engineer, manufacturer specification, or the relevant technical standard. For the formulas on their own, see the formula reference.
Related Resources
- Guides & Blogs . Guides and blog posts on how to use our calculators and understand the concepts behind them.
- Formulas . The exact formulas behind each calculator, with the notation and reasoning explained.
- Glossary . Short definitions of the terms you will meet across our calculators, including BMI, BMR, amortization, and more.
- Methodology . How we choose formulas, test calculations, round results, select sources, and review our tools.
Recent Guides
View All →How To Calculate 3 Phase Motor Power
Learn how to calculate 3-phase motor power from the nameplate. Walk through a real scenario converting horsepower to kilowatts using motor efficiency.
Read the Guide3 Phase Power Calculation Formula
Learn how to calculate 3-phase real power using the standard formula. Walk through a complete calculation using line voltage, current, and power factor.
Read the GuideFrequently asked questions
What engineering calculations can I do here?
Electrical power conversions, fluid flow and friction loss, machining speeds, gear ratios, agricultural field rates, and computing performance metrics, among others. Each page states exactly which formula and convention it uses.
Are these calculators reliable for professional engineering work?
They are estimating and educational tools, not a substitute for a professional engineer, manufacturer specification, or the relevant technical standard. For safety-critical or code-governed work, always verify results with a qualified professional.
Are the engineering calculators free to use?
Yes, every tool here is free, with no sign-up and no limit.