About Calcify

Our Calculators

• Pregnancy Calculator — Track due dates and pregnancy milestones
• Age Calculator — Calculate exact age in years, months, and days
• Tip Calculator — Split bills and calculate tips easily
• Date Calculator — Find the difference between dates or add/subtract days
• Percentage Calculator — Solve any percentage problem
• Tariff Calculator — Calculate import tariffs with 2025 rates
• Mortgage Calculator — Estimate monthly payments with amortization
• Tax Calculator — Federal and state income tax estimates for 2025

Why Calcify?

• Method-focused — Built from standard formulas and, where relevant, primary sources such as IRS publications
• Instant — Results update as you type, no page reloads
• Free to use — No account or subscription is required
• No Account Required — Just open and calculate

Our Mission

At Calcify, our mission is to democratize access to financial and mathematical tools that were once locked behind expensive software or required specialized knowledge. We believe that everyone — from first-time homebuyers estimating mortgage payments to expectant parents tracking pregnancy milestones — deserves accurate, reliable calculation tools at their fingertips. Too often, people make critical life decisions without the right numbers in front of them, simply because the tools are hard to find or difficult to use. We are committed to changing that by keeping every calculator on Calcify completely free, with no paywalls, no premium tiers, and no account sign-ups. Whether you are filing taxes, splitting a dinner bill, or figuring out import duties, you should not need a finance degree or a spreadsheet to get the answer. Our goal is to empower informed decision-making for everyone, regardless of their technical expertise or background.

How We Build Our Calculators

Every calculator on Calcify is built with real-world accuracy as the top priority. We do not cut corners or rely on rough estimates — each tool is grounded in authoritative data and proven formulas. Our federal and state tax calculators use brackets sourced from IRS publications and should be checked against the tax year shown on the tool. The mortgage calculator follows standard amortization methods used by lenders, giving you a month-by-month breakdown to review. Our pregnancy calculator is based on established medical guidelines, including Naegele's Rule, which is the same method obstetricians use to estimate due dates. Importantly, all calculations run entirely client-side in your browser — your inputs never leave your device, which means your financial details and personal information stay on your device. Rates and source data can change, so the tool and article pages identify their scope and should be checked against current primary sources before a high-stakes decision.

Data Sources

Accuracy starts with trustworthy data. Our calculators draw from the following official sources:

• IRS (Internal Revenue Service) — Federal tax brackets, standard deductions, and filing thresholds
• Tax Foundation — State-level tax rate comparisons and policy data
• ACOG (American College of Obstetricians and Gynecologists) — Clinical guidelines for pregnancy date calculations
• Standard Financial Formulas — Mortgage amortization, compound interest, and payment schedules
• US Customs and Border Protection / USITC — Harmonized tariff schedule and import duty rates

Learn More on Our Blog

Want to dive deeper? Visit our blog for in-depth guides on topics like how mortgage payments are calculated, understanding federal and state tax brackets, tipping etiquette around the world, and much more. We publish practical, plain-language articles to help you get the most out of every calculator on Calcify.