About OmniCalcX

Why I Built This

A few years back, I needed to run a quick compound interest calculation. I Googled it, clicked the first result, and landed on a site that had seven ads above the fold, a calculator that didn't even work on my phone, and a two-minute timer before it would show me the answer. I closed the tab and built my own.

That's really all OmniCalcX is — a collection of tools I built because the alternatives were frustrating. I kept adding more as I ran into new problems: figuring out my TDEE for a fitness goal, comparing mortgage rates when house shopping, calculating gas cost for a road trip. Each one started as a personal tool that I cleaned up and published.

OmniCalcX has grown into a toolkit of 60+ tools — calculators, decision guides, and planners — organized around the decisions people face every day: money, health, home, and everyday life.

How I Keep Things Accurate

Since some of these tools deal with money and health data, I take accuracy seriously. Here's my process:

1. Research first. Before building any tool, I look up the standard formulas from authoritative sources — NIST for unit conversions, the CDC/WHO for BMI and calorie calculations, standard financial formulas from textbooks and the CFPB for anything money-related.
2. Test against known values.Every tool gets tested with manually calculated examples. For the mortgage calculator, I verified results against Bankrate's calculator and my own spreadsheet. For BMI, I cross-checked with the CDC's adult BMI calculator.
3. Read the feedback.When someone emails me about a wrong result or confusing behavior, I fix it. I've caught several rounding edge cases this way that I would have missed otherwise.
4. Update when standards change. Tax brackets, BMI classifications for children (which use CDC growth charts), and other standards change over time. I revisit these tools periodically.

Data Sources & References

The tools on this site use formulas and data from these sources:

• Unit conversions: National Institute of Standards and Technology (NIST) conversion factors
• BMI calculations:CDC and WHO standard BMI formulas; CDC growth charts for children's BMI percentiles
• Calorie/TDEE: Mifflin-St Jeor equation, validated against NIH recommendations
• Financial calculators: Standard amortization formulas; CFPB (Consumer Financial Protection Bureau) guidelines for mortgage and loan calculations
• Statistical functions: Standard formulas as found in introductory statistics textbooks (mean, standard deviation, probability distributions)

While I strive for accuracy, these tools are for informational purposes. For medical, legal, or financial decisions, always consult a qualified professional.

Editorial Policy

The blog articles on OmniCalcX are written to genuinely help people understand the math behind everyday decisions. Each article goes through a simple editorial process:

1. Choose a topic based on what people actually search for
2. Research the math, the common misconceptions, and practical examples
3. Write the article with real examples, not generic filler
4. Test the examples in the corresponding calculator to make sure they match
5. Review for clarity — if I can't explain it simply, I rewrite it

What We Offer

Tools organized around life's decisions, not just raw calculations:

• Money: Mortgage, car payment, compound interest, retirement, and ROI calculators — plus decision guides to help you navigate financial choices
• Health: BMI, BMR, calorie, protein, and body fat calculators — plus guides to understand what your numbers mean
• Home & DIY: Concrete, paint, electricity cost, and fuel calculators for home projects
• Everyday: Tip, discount, date, time, and unit conversion tools for daily moments
• Learn: In-depth articles explaining the math and reasoning behind everyday decisions

Disclaimer

The tools and information on OmniCalcX are for general informational purposes only. They do not constitute financial, medical, legal, or professional advice. Always consult qualified professionals before making important financial, health, or legal decisions. Results from our tools are estimates and may not reflect your exact circumstances.

Our Principles

• Free forever.No paywalls, no premium tiers, no "upgrade to unlock" nonsense.
• Accurate and transparent. Formulas are documented on each tool page. If you want to verify the math, you can.
• Fast and lightweight.The site loads quickly because it doesn't need to load 50 tracking scripts. Pages are optimized for performance, not ad impressions.
• Privacy-first.I don't collect personal data, don't require accounts, and don't track you across the web. See the Privacy Policy for details.

Get in Touch

Have feedback, want to suggest a new tool, or found a calculation that seems off? Email me directly at [email protected]. I read every message and usually respond within a day or two.

Last updated: April 2026