Keisan Tools

What it does

468 free online calculators covering tax, finance, health, unit conversion, math, date, everyday life, and programming. No ads, no sign-up, no popups. Every calculation runs client-side — your data never leaves your browser. Built with Next.js SSG for sub-second load times. Japanese and English bilingual support. New calculators added weekly based on user requests. From BMI and loan payments to hex converters and regex testers — if you need to calculate it, it's probably here.

税金、給与、年金、BMI、保育料、ROIなど、計算根拠と公的資料を確認した無料オンライン計算ツール。スマホ対応、登録不要。

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  CalculatingHub2025 · calculatinghub.com · ▲11

  I Built a Comprehensive Suite of Free Online Tools: 300+ Calculators, Converters, and Random Generators After months of coding and development, I'm excited to share my website offering a vast collection of free online calculators, unit converters, and random generators all in one place. This project was created to simplify everyday tasks and provide accurate tools for various needs. What You'll Find on My Site: Calculators: - Financial tools: ROI, APY, mortgage calculators - Business tools: Break-even, commission calculators - Mathematics: From basic to advanced functions - Health: BMI, BMR,…

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  ToolRef.com2025 · ▲6

  Free online tools & calculators

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  Free Online Tools2025 · minitools4u.com · ▲14

  Hi HN! I built ToolDexo - a collection of 29 free online tools because I was tired of websites that force you to sign up just to use a calculator or word counter. What's included: - Calculators: BMI, calorie, mortgage, loan, tax, grade, tip, percentage, age, compound interest - Converters: Currency (36 currencies with live rates), unit, timezone, file size - Generators: Password, QR code, favicon, color picker, Lorem Ipsum, random number - Text tools: Word counter, case converter, character counter, text compare, Markdown editor - Dev tools: JSON formatter, Base64 encoder/decoder Tech…

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  Calculator.FreeJul 2026 · calculator.free · ▲8

  Calculator.Free offers 200+ free online calculators — mortgage, loan, income tax, BMI, percentage and more. Fast, accurate, mobile-friendly, no sign-up.

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  Today Calculator2025 · todaycalculator.com · ▲7

  Today Calculator offers 5000+ free online calculators for math, finance, health, unit conversions, and daily life calculations. Fast, accurate, and easy to use on any device

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  taxcalculatorsuk.co.uk2025 · taxcalculatorsuk.co.uk · ▲5

  25+ free UK tools for finance, wellness & daily life

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  /dev/null▲486

  a social network for devs

  Dev tools · 3d ago · dev-null.sh

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  Whiteboard (YC W26) – an open-source IDE for thoughtful software design▲423

  open-source IDE for thoughtful software design. Contribute to devdotfast/whiteboard development by creating an account on GitHub.

  Dev tools · 28d ago · github.com

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  Reladraw – A diagram language where you decide where to place things▲411

  Contribute to reladraw/reladraw development by creating an account on GitHub.

  Dev tools · 26d ago · github.com

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  OpenBot▲362

  Grok Bot alternative: free, local, open-source, multiplayer

  Dev tools · 23d ago · openbot.run

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  Talanoa▲346

  Hi HN, I’m a fullstack developer, and honestly, I’ve lost count of how many side projects I’ve worked on over the years. But one idea kept coming back to me: a different kind of email client. It first came to me in 2014: “What if we could handle emails more like conversations?” Every year, I’d revisit this concept in my “Build Notes.” Ten years later, no one had built exactly what I had in mind — so I finally decided to do it myself. That’s how Talanoa was born. I wanted something focused on people, not timelines. I was tired of marking messages as unread just to remember to reply later, or…

  Dev tools · 21d ago · talanoa.email

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  CoreSpeed▲332

  One MCP for everything your agents need: apps, memory, tools

  Dev tools · 28d ago · corespeed.io

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  Brila▲1,364

  One-page websites from real Google Maps reviews

  AI · Apr 2026 · brila.ai

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  A game where you build a GPU▲964

  Thought the resources for GPU arch were lacking, so here we are

  Life & fun · Apr 2026 · jaso1024.com

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  I built a tiny LLM to demystify how language models work▲915

  Built a ~9M param LLM from scratch to understand how they actually work. Vanilla transformer, 60K synthetic conversations, ~130 lines of PyTorch. Trains in 5 min on a free Colab T4. The fish thinks the meaning of life is food. Fork it and swap the personality for your own character.

  AI · Apr 2026 · github.com

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  Fathom 3.0▲800

  AI meeting notes: now bot-free, in ChatGPT & Claude + more

  AI · Apr 2026 · fathom.ai

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  Brutalist Concrete Laptop Stand (2024)▲786

  I made a laptop stand out of solid concrete, in the style of brutalist architecture, with themes of urbex and urban decay

  Life & fun · Apr 2026 · sam-burns.com

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  I built a frontpage for personal blogs▲783

  With social media and now AI, its important to keep the indie web alive. There are many people who write frequently. Blogosphere tries to highlight them by fetching the recent posts from personal blogs across many categories. There are two versions: Minimal (HN-inspired, fast, static): https://text.blogosphere.app/ Non-minimal: https://blogosphere.app/ If you don't find your blog (or your favorite ones), please add them. I will review and approve it.

  AI · Apr 2026 · text.blogosphere.app