How To Calculate

What this page owns

About is the product story and the evidence map. It is not a second biography and not a sales brochure. Use it to understand what How To Calculate is accountable for.

• Mission and product promise in plain language.
• Verifiable claims (client-side math, named editor, correction path) you can check without trusting marketing copy.
• Clear handoffs to the author page, editorial policy, and disclaimers.

Framing: product accountability with a public evidence strip, not a twin-board blog guide and not a person-profile page.

Evidence you can check

Trust claims should leave a trail. Each row below is something you can verify on this site without a press quote.

1. 01 · TOOL COUNT

   168+ calculators in the live registry

   Browse the homepage or any cluster hub. The count comes from the same search registry the site uses in production, not a rounded marketing slogan.

2. 02 · CLIENT-SIDE CORE

   Core calculator math runs in your browser

   For standard tools, inputs are not uploaded to get a result. Optional share links, analytics, ads, and Pro features are separate. Details live in the Privacy Policy.

3. 03 · FORMULA-FIRST PAGES

   Formulas, units, and assumptions are published on the tool pages

   Renewed calculators show worked examples, edge cases, and sources. Methodology standards are written out on the Editorial Policy.

4. 04 · NAMED EDITOR

   One real person stands behind the library

   Ahmet C. Toplutaş is the site owner and editor. Credentials and selected work sit on the author page. There is no anonymous “expert board” byline on this site.

5. 05 · CORRECTION PATH

   Material errors have a public intake route

   Send a URL, expected result, and a primary source when possible via Contact or cihattoplutas@gmail.com.

Why it exists

Many free calculators disagree with each other and never show why. Two mortgage tools can print different payments when one includes escrow and the other does not. Two BMI tools can disagree when height units are mishandled. The product thesis is simple: show the formula, name the assumptions, and keep the math inspectable.

How To Calculate started as a practical library for decisions people already make (housing, health metrics, tax sketches, DIY quantities) and grew into a broader set of tools under the same rule: accuracy of the model first, clarity of the interface always. The goal is confident planning literacy, not a black-box oracle.

That is also why guides exist beside tools. A calculator answers “what is the number.” A guide answers “which number matters for this decision,” then hands you back to the panel.

How we build tools

Full methodology lives on the editorial page. The short version:

Read the full standards on Editorial Policy & Methodology.

What we publish

Three surfaces, one library: interactive calculators, cluster hubs that act as decision maps, and guides that teach a decision then hand off to a tool.

• 01FinanceMortgage, loans, tax, investing, retirement
• 02HealthBMI, TDEE, macros, pregnancy timing tools
• 03BlockchainGas, IL, staking, crypto tax sketches
• 04BusinessMargins, churn, unit economics
• 05MathPercentages, matrices, statistics helpers
• 06Home & DIYPaint, concrete, stairs, flooring
• 07LifestyleSleep cycles, tips, everyday utilities
• 08GuidesDecision articles that hand off to tools

Who stands behind it

How To Calculate is built and edited by Ahmet C. Toplutaş, a Boğaziçi University Mechanical Engineering graduate and B2B SaaS operator working across finance, operations, and product. The engineering habit shows up as systems thinking: break the problem down, name the model, check the edge cases.

Person-level credentials, methodology notes, and selected work belong on the author page so About stays product-focused. If you need a correction or a partnership note, use Contact.

Limits we state plainly

Accountability includes what we refuse to claim.

• No fabricated user testimonials or anonymous “expert review board” bylines.
• No promise that a calculator output is personalized advice for your taxes, loans, investments, or medical care.
• No claim that every page has been reviewed by an outside physician or financial planner. Named review only appears when a real named reviewer exists.
• Models can be wrong for your jurisdiction, fees, body composition, or edge case. Sources and disclaimers exist so you can spot the gap.

Scope and liability language: Disclaimers · Terms of Use · Privacy Policy.

Trust map

One job per page. Use this map instead of hunting the footer.

• AboutProduct mission and evidence (this page).
• AuthorPerson graph, credentials, selected work.
• Editorial policySources, review cadence, corrections process.
• DisclaimersYMYL limits for money and health tools.
• ContactCorrections, media, and partnership notes.
• MediaCitations and coverage requests via Contact.

FAQ

What is How To Calculate?

How To Calculate is a free online library of calculators and decision guides for finance, health, math, crypto, home projects, and everyday planning. Tools are built to show formulas and assumptions, not just a final number.

Do you store my calculator inputs?

Core calculator math runs in your browser. Inputs for those tools stay on your device for the session unless a page explicitly offers an optional save or share feature. See the Privacy Policy for cookies, analytics, and any Pro features.

Are the calculators professional advice?

No. Results are educational planning sketches. They are not tax, legal, lending, investment, or medical advice. Read Disclaimers before relying on any YMYL calculation.

Who writes and maintains the site?

Ahmet C. Toplutaş is the site owner and editor. There is no fictitious review board. Methodology, sources, and corrections are documented on the Editorial Policy and Author pages.

How do I report an error?

Send the page URL, what you expected, and a primary source if you have one to cihattoplutas@gmail.com or use the Contact page. Material formula or unit errors are investigated and corrected.