Tools that stay out of your way.
CalcuOnline is a collection of precise, private, browser-based instruments for finance, construction, and developer work — built and maintained by a single engineer.
What CalcuOnline is
CalcuOnline started as an internal tool kit — a place to keep the financial and engineering calculations that came up repeatedly while building eInvit. EMI estimates for event budgets, material quantities for venue work, unit conversions, tax figures. They kept getting rebuilt from scratch in spreadsheets.
Rather than keep them private, we turned them into a public site — free to use, no account required, with enough depth (charts, schedules, PDF export, live currency rates) to be genuinely useful beyond a quick Google search.
Every tool is a single-page web app that computes entirely in your browser. Nothing you type is transmitted, stored, or logged by us.
Tony Augustine Labs
CalcuOnline is designed, engineered, and maintained by Tony Augustine, the sole engineer and product owner at Tony Augustine Labs (TAL) — an independent software studio focused on wedding-tech and productivity tools for South Asian markets.
Our primary product is eInvit, a digital invitation SaaS for Indian weddings and events — RSVP tracking, guest management, WhatsApp reminders, QR check-in, gift registries, and themed Card Studio with nine invitation layouts. CalcuOnline is a free companion utility that sits alongside it.
We are a lean team. That means every tool is built to a high standard of correctness, maintained with care, and updated when formulas or design need improving. If you spot an error in a calculation or a design issue, we want to know — get in touch.
Our values
Every calculation runs locally in your browser. Nothing you type is sent to any server we control. The only external calls are the live exchange-rate fetch (from a public CDN) and the anonymous visitor counter.
Results update in real time as you type — no submit button, no loading spinner, no round trip to a server. Speed is a feature.
Every formula is documented in the tool. We use standard financial and engineering formulas and show our working, so you can verify results against any textbook or spreadsheet.
Finance tools export results to PDF and CSV, so you can drop the output directly into a report or share it with a colleague.
CalcuOnline is completely ad-free. We build this as a companion to our main product, eInvit, and our incentive is quality — not page views.
Currency selectors on all finance tools, 40+ currencies in the converter, and unit systems chosen to cover the most common engineering standards worldwide.
Roadmap
CalcuOnline is actively developed. Planned additions include:
- →SIP / SWP return calculator for Indian mutual fund investors
- →Structural beam load calculator for civil engineers
- →Net salary (CTC to take-home) calculator
- →Hash generator (MD5, SHA-1, SHA-256)
- →Cron expression builder and explainer
- →Percentage / ratio / proportion calculator
Have a specific tool you need? Request it here.
Planning a wedding or event?
eInvit — our digital invitation platform for Indian weddings and events. RSVP tracking, WhatsApp reminders, gift registries. Free to start.
Visit eInvit.in →