
HubCalc
Fast, clean, and free online productivity calculators
What it does
Free, privacy-focuHubCalc is a lightweight suite of fast, privacy-focused online calculators built for everyday productivity. Featuring zero ads, instant real-time calculations, dark mode, and a distraction-free experience. Includes tools for hourly wage analysis, invoice VAT calculation, CPM ad budget planning, percentage changes, and more.sed online calculators for freelancers, business invoicing, and daily math productivity.
Free, privacy-focused online calculators for freelancers, business invoicing, and daily math productivity.
Calculate your target hourly rate based on desired annual income and working hours. Easily calculate pre-tax amounts, sales tax/VAT, or extract tax from invoice total. Quickly determine final sale price and total money saved during percentage discounts. Calculate ad campaign CPM, total ad spending, or estimated creator ad revenue. Calculate percentage increase or decrease between initial and final values. Estimate monthly mortgage payments, interest rates, and loan terms easily. Calculate transaction processing fees or determine how much to invoice to receive your exact target amount. Can't find the tool you're looking for? Tell us what you need and we'll build itfrom hub-calc.pages.dev
Does the same job
all alternatives →
theproductivitycalc.com30d ago · theproductivitycalc.com · ▲1Free productivity calculators for smarter work.




More dev tools this month
the category →



Open-source GTM skills for technical founders
Dev tools · 29d ago · gtmcofounder.com

OpenTrailPaper is open-source bike computer firmware for the LilyGO T5S3 4.7" E-Paper PRO. It supports offline maps, GPX routes, FIT recording and Bluetooth sensors.
Dev tools · 1d ago · opentrailpaper.com

Launched alongside, August 2026
the whole month →- TL
Life & fun · 10d ago · louisabraham.github.io


- SA
Hello HN! I found that picking out plausible but diverse skin tones for my digital art and game development projects was kind of difficult, and I got curious about if there was a way to define a color space that made it easy. I've built a color picker and procedural generation algorithm based on the space as well as a bunch of other fun js features and demos throughout the page that use the equations. If you find it interesting, I have lots of explanations of how I built it and what properties the space has. The methodology might be a bit shaky, but hopefully the result is as helpful for…
Life & fun · Aug 2026 · toneyalexander.github.io


I trained a 125M-parameter transformer to autocomplete piano performances in real time (~108 notes/sec on an iPhone 15). The idea is basically GitHub Copilot or Tabnine, except instead of prompting it with code, you prompt it by playing a few notes on a MIDI piano. The model then continues what you played, entirely on-device. The app is free if anyone wants to try it. Happy to answer questions about the model, training, Core ML, or the many things that didn't work.
AI · 16d ago · simedw.com