SpecCalc Hub

What it does

Free web calculators for energy, solar, battery runtime, UPS runtime, EV charging cost, voltage drop, wire-size estimates, Ohm's law, voltage divider, and resistor calculations. Each calculator shows formulas, assumptions, limitations, and result logic so users can understand the estimate instead of relying on a black box.

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  FreeWWW Engineering Calculator SuiteJul 2026 · freewww.com · ▲3

  Twenty-two calculators for everyday engineering problems

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  EcoEnergyCalcJun 2026 · ecoenergycalc.com · ▲2

  Free energy & carbon footprint calculators. No signup.

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  HowMuchWattsJul 2026 · howmuchwatts.com · ▲5

  50 free calculators for home energy costs & savings

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  CampPowerCalcJun 2026 · camppowercalc.com · ▲2

  Calculate exact battery + solar for your van build

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  VoltFlow.netApr 2026

  Power your Life Smarter

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  SolarCalcProApr 2026 · solarcalcpro.com · ▲1

  Calculate Solar Savings, Battery Size & EV Costs for US

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  Dograh▲592

  The open source VAPI alternative

  Dev tools · 25d ago · dograh.com

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  Meridian▲530

  Don't let your work go unnoticed. Get promoted!

  Dev tools · 20d ago · meridiona.com

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  x1▲516

  Lovable for iPhone apps go from idea to App Store

  Dev tools · 11d ago · x1.new

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  Computable GPU Index (CGI)▲424

  The first open-source price index for GPU compute Discussion | Link

  Dev tools · 10d ago · producthunt.com

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  The GTM Co-Founder▲402

  Open-source GTM skills for technical founders

  Dev tools · 29d ago · gtmcofounder.com

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  Open-Source eInk Bike Computer▲399

  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 · 2d ago · opentrailpaper.com

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  Brew ▲905

  Like Claude design for email marketing

  AI · May 2026 · brew.new

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  Kilo Code for VS Code▲897

  Parallel agents, diff reviewer, and multi-model comparisons

  Dev tools · May 2026 · kilo.ai

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  StoreClaw▲805

  Grow your store profits with agents that know how to sell

  AI · May 2026 · storeclaw.ai

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  PollyReach▲796

  Give your agent a real number and voice to make calls.

  AI · May 2026 · pollyreach.ai

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  Needle: We Distilled Gemini Tool Calling into a 26M Model▲776

  Hey HN, Henry here from Cactus. We open-sourced Needle, a 26M parameter function-calling (tool use) model. It runs at 6000 tok/s prefill and 1200 tok/s decode on consumer devices. We were always frustrated by the little effort made towards building agentic models that run on budget phones, so we conducted investigations that led to an observation: agentic experiences are built upon tool calling, and massive models are overkill for it. Tool calling is fundamentally retrieval-and-assembly (match query to tool name, extract argument values, emit JSON), not reasoning. Cross-attention…

  Life & fun · May 2026 · github.com

• FM
  Files.md – Open-source alternative to Obsidian▲730

  Dev tools · May 2026 · github.com