Free Engineering Calculators

Tools for Engineers & Students

Practical calculators built from real engineering experience — power electronics, energy systems, and electrical design. Free, no signup required.

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EV & Transport

EV Cost & Savings Calculator

Compare electricity vs petrol, diesel or CNG running costs for 2W, 3W and 4W EVs in India. Charging time, battery health and 5-year projection.

Solar Energy

Solar PV Panel Sizing Calculator

Calculate panels needed, inverter size, roof area, annual savings and payback period for residential and commercial solar systems in India.

Battery & UPS

Battery Sizing & UPS Backup Calculator

Calculate battery bank capacity, number of batteries, actual backup time and estimated cost. Supports lead acid, AGM, LiFePO4 and NMC.

Power Electronics

Electrolytic Capacitor Lifetime Calculator

Calculate DC-link capacitor expected lifetime from temperature, ripple current and voltage stress. Based on published research in JEET (Springer, 2023).

Electrical Design

Transformer Sizing Calculator

Calculate the required kVA rating from connected loads, power factor, demand factor and growth margin. Selects standard IS/IEC sizes automatically.

EV & Mobility

EV Charging Time Calculator

Calculate how long it takes to charge any EV with any charger type — from 5A home socket to 150kW DC fast charger. Covers all popular Indian EV models.

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🆕 New — Interactive Tool

Which DC-DC Converter Topology Should I Use?

Answer 3–4 questions about your design requirements — get an instant topology recommendation covering Buck, Boost, Buck-Boost, Flyback, Forward, LLC and SEPIC. With pros/cons, specs and application guidance.

7 topologies Students & engineers Pros/cons table Interactive

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🆕 New — Engineering Calculator

DC-DC Duty Cycle & Component Calculator

Calculate duty cycle, inductor value, capacitor, peak switch current and timing for Buck, Boost, Buck-Boost, Flyback and Forward converters — with step-by-step formula working and component selection tips.

5 topologies Full formula working Component tips Students & engineers

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🆕 New - PCB Design

PCB Trace Width, Resistance & Temperature Calculator

IPC-2221 based trace width calculation with resistance, voltage drop, temperature rise, fusing current and practical design suggestions to reduce trace resistance.

IPC-2221 Ext & Int layers Temp coefficient Design tips

Coming Soon

More calculators in development. Suggest one via the contact page.

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Electricity Bill Calculator

Appliance-wise monthly cost

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Power Factor Correction

Capacitor bank sizing

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Cable Size Calculator

Current capacity & voltage drop

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Motor Starting Current

DOL vs Star-Delta

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