Software studio · Jerusalen Tools
Free online calculators and tools
Free interactive calculators for finance, health, dates and more. Instant results, no sign-up, with step-by-step explanations.
- 86+
- tools & projects
- 2025
- operating since
- 3
- languages
- 100%
- in your browser
Featured tools
- TopSquare footage calculatorMultiply length by width to get square footage instantly, with automatic conversion to square meters and square yards. Works in feet or meters, free.
- TopDays Between Dates CalculatorFind the exact number of days between two dates, plus full weeks and leftover days. Free, instant and accurate with leap years from 1900 to 2100.
- TopHours calculator: work hours between two timesAdd up your work hours between clock-in and clock-out, subtract the lunch break and get the total in hours and minutes or in decimal format for payroll.
- TopAmortization CalculatorWork out your fixed monthly payment, total cost and lifetime interest for any mortgage, auto or personal loan with the standard amortization formula.
- TopCAGR Calculator (Compound Annual Growth Rate)Calculate CAGR from a beginning value, an ending value and the number of years. Also returns the total return and the growth multiple.
- TopVRT Calculator Ireland 2026 (CO2 + NOx)Estimate your Irish Vehicle Registration Tax with the official 2026 Revenue.ie table: 20 CO2 bands (7%-41% of OMSP) plus the NOx levy per mg/km.
About us
The studio behind 86+ tools and projects
Jerusalen Tools is an independent software studio. These free calculators are our public lab: hundreds of fast, typed, tested micro-apps. We apply the same engineering to build custom software for companies and individuals.
What we build
From prototype to product: fast, accessible apps, ready to grow.
- Web applicationsFast, accessible apps, dashboards and portals, ready to scale.
- Calculators & toolsCustom, embeddable calculators — just like the ones on this site.
- Automation & integrationsConnect your systems, APIs and workflows to save hours of manual work.
- Performance & technical SEOCore Web Vitals, load speed and international SEO done right.
Why work with us
The same technical standard we apply to our tools, applied to your project.
- Typed and tested codeTypeScript, automated tests and human review on every release.
- Fast by designBuilt for Core Web Vitals: instant loads and zero needless weight.
- Multilingual by defaultProducts in several languages, with international SEO from day one.
- Privacy firstWhen possible, everything runs in the browser; we never sell your data.
All tools
Finance
- Amortization Calculator
- Superannuation Calculator 2026 (project your retirement balance)
- CAGR Calculator (Compound Annual Growth Rate)
- Car Loan Calculator
- Compound interest calculator
- Discount calculator
- eBay Fee Calculator
- Inflation calculator
- Gross to Net Salary Calculator
- Retirement savings calculator
- Simple interest calculator
- Tip Calculator
How it works
- 1Pick a toolSearch or browse categories until you find the calculator you need.
- 2Enter your numbersNo sign-up: everything runs in your browser and nothing is uploaded.
- 3Get the resultInstantly, with its explanation, formula and step-by-step examples.
Have a project in mind?
Tell us what you need and we'll reply with the next steps. The first consultation is free and with no commitment.