Privacy-first tools for real-world decisions

Problem Solving Engine

Free calculators, estimators, planners, and standards-aware answers across 9 categories.

No user profiles

No accounts, no profiles, and no behavioral tracking. Calculator inputs stay in your browser.

Built for professionals and enthusiasts

Useful for contractors, operators, analysts, builders, students, and curious power users.

Standards-aware answers

Uses industry standards, official references, and confidence tiers to keep answers grounded.

No fabricated precision

When the engine cannot answer precisely, it says so instead of guessing.

Featured Tools

🏗️

Calculate how much concrete you need for slabs, footings, and pours.

🚗

Calculate your monthly car payment and total cost, including down payment, trade-in, and sales tax.

⚖️

Calculate your Body Mass Index (BMI) and see which WHO category it falls into.

🧳

Generate a customized packing list based on your trip length, climate, and planned activities.

💱

Convert between major world currencies using reference exchange rates.

📊

Get a suggested investment approach based on your risk tolerance and time horizon.