Business Days Calculator
Count calendar days, weekdays and optional 2026 public-holiday exclusions for Austria or Croatia.
- Deadline and project planning use case
- Optional inclusive counting
- No external API dependency
Tool library
Small calculators with serious structure.
Each tool is designed as a search landing page and a useful calculator: clear inputs, receipt-style output, formula, worked example, limitations and related tools. The goal is long-term search traffic without sacrificing professional tone.
Implemented first cluster
Date, invoice, VAT and margin calculators.
These are the low-maintenance, low-regulation tools that fit an AdSense model: useful arithmetic, no login, no uploads, no regulated advice.
Invoice Due Date Calculator
Add payment terms to an invoice date and optionally roll the due date to the next working day.
- 7, 14, 30, 45 and 60 day terms
- Weekend adjustment
- Austria/Croatia holiday option
VAT Calculator Austria
Calculate Austrian VAT from net or gross amounts using 20%, 13%, 10% or a custom rate.
- Net to gross and gross to net
- Exact cent rounding
- Formula shown with result
VAT Calculator Croatia
Calculate Croatian PDV/VAT from net or gross amounts using 25%, 13%, 5% or a custom rate.
- Retail and invoice arithmetic
- Exact cent rounding
- Arithmetic only, not filing advice
Margin & Markup Calculator
Convert cost and price into profit, margin, markup and target price for a desired margin.
- Small seller and service pricing
- Cent-safe arithmetic
- Good internal link target for future seller tools
Home and seller calculators
Paint, tile, flooring, moving boxes, Etsy/Gumroad profit and product-price calculators are the next SEO clusters.
- Home improvement has commercial ad intent
- Seller tools fit Altoria's numbers profile
- Build only after the first cluster is indexed