Free Engineering Calculators for IEC, IEEE, ISA, API & ASME Standards

Professional grade tools for Electrical, Instrumentation, and Mechanical Engineers. Simplified.

50+ Countries
100+ Calculators
Thousands Calculations Run

Why Trust Design Calculators?

We are more than just a tool; we are your partner in precision engineering. Dedicated to empowering the community with free, transparent, and standard-compliant tools.

Guided by Standards

Our algorithms are strictly based on international standards including IEC, IEEE, ASME, API, and ISO, ensuring your results are audit-ready and professional.

Completely Free

We believe engineering safety shouldn't have a paywall. All our professional-grade tools are free to use, supported by the community and minimal ads.

Educational Value

We don't just give answers; we show the math. Detailed steps and formula explanations help you verify results and deepen your understanding.

Unlock Your Solution in 3 Simple Steps

1

Input Your Parameters

Select your calculator and enter your project-specific data into the intuitive interface.

2

Get Instant Results

Our powerful engine processes your data instantly, providing the final, accurate answer.

3

Review Every Step

This is our unique value. Expand the detailed breakdown to see the full calculation, from formula to finish.

Guided by Global Standards

Our credibility is rooted in referencing the world's most respected engineering authorities. Our tools are inspired by the methodologies and principles recommended by respected global engineering organizations. We reference widely recognized practices to maintain consistency, reliability, and clarity in every calculation. While our resources draw from established standards, they are intended for informational and educational purposes — helping users understand and apply sound engineering concepts with confidence.

Engineering FAQ

Common questions about our standards, accuracy, and usage.

What IEC standards are used?

Our calculators primarily reference IEC 60364 for electrical installations, IEC 60909 for short-circuit currents, and IEC 61508 for functional safety. Each calculator page cites the specific standard used for transparency.

Are results suitable for detailed engineering?

Yes, but with verification. While our tools use industry-standard formulas and factors, all results should be verified by a qualified engineer. They are excellent for reliable estimates, front-end engineering design (FEED), and quick validation.

How often are calculators updated?

We review our tools quarterly to ensure alignment with the latest standard revisions (e.g., when a new IEEE or IEC version is released). We also continuously update them based on user feedback.

Are formulas referenced?

Absolutely. We believe in "White Box" calculation. Every tool includes a "Formula & Calculation Details" section (often hidden by default) that shows the exact equations and logic used.

Can results be exported?

Currently, you can print the results page to PDF (Ctrl+P) which is formatted for reports. We are working on a direct "Export to Excel/PDF" feature for registered users.

Do you support both SI and Imperial units?

Most of our calculators are designed with global engineers in mind and offer automatic conversion or specific fields for both Metric (SI) and Imperial units.

Is my calculation data saved?

No. We prioritize your privacy. All calculations are performed client-side in your browser. We do not store your project data or input parameters on our servers.

Is registration required to use the tools?

No. All tools on Design Calculators are currently free and open for public use without any registration or login barriers.

Can I request a specific calculator?

Yes! We value community feedback. If you have a specific standard or calculation you need, please contact us via the "Contact" page, and we will consider adding it to our roadmap.

Are these tools free for commercial use?

Yes, you are free to use these tools for your commercial engineering projects. However, please read our Terms of Service regarding liability—user verification is always required.

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Meet the Creator

Anil Sharma, Senior Technical Professional

Developed by Anil Sharma, a Senior Technical Professional with 25+ years in Industrial Engineering. This site was born from a passion to provide transparent, reliable, and accessible tools for fellow engineers and students.

All calculators are meticulously developed based on global standards to ensure you get the right answers, and more importantly, understand *how* you got them.

Read My Full Story & Mission