Every tool, in one place.
22 tools across six categories — every one explained, sourced, and built for clarity.
Finance
Mortgages, margins, salary, loans, investing — fast answers with the math shown.
Mortgage + Extra Payment
See your monthly payment, total interest, and exactly how many years extra principal saves. Compare scenarios A vs B side-by-side.
Margin & Markup Calculator
Calculate gross margin, markup, profit, and selling price from any two inputs. Built for ecommerce and SaaS operators who need the answer in seconds.
Salary → Hourly
Convert annual salary to hourly, weekly, bi-weekly, or monthly pay. Supports custom hours/week and PTO weeks/year.
Student Loan Payoff
See your payoff date and total interest. Test how a target monthly payment, lump sum, or refinance rate accelerates payoff.
Compound Interest
Project growth from a starting balance, monthly contribution, return rate, and time horizon. See contribution vs. interest split year-by-year.
Health & Fitness
Macros, calories, weight, pregnancy, peptides — backed by primary research.
TDEE Calculator
Calculate your Total Daily Energy Expenditure (TDEE) with Mifflin–St Jeor accuracy, then see your protein, carb, and fat targets for cut, maintain, or bulk.
Keto Macro Calculator
Get your exact ketogenic macros: under 20 g net carbs, 0.7–1.0 g/lb protein, the rest from fat. Built for cut, maintain, and lean-bulk modes.
Calorie Deficit Calculator
See exactly how long it takes to hit your goal weight at any deficit size. Built around the 3,500 kcal-per-pound rule with metabolic-adaptation correction.
Pregnancy Weight Gain Calculator
See your trimester-by-trimester healthy weight-gain range based on pre-pregnancy BMI. Backed by Institute of Medicine guidelines.
Peptide Dosage Calculator
Convert peptide vial mg, BAC water mL, and target dose mcg into precise insulin-syringe units. Supports BPC-157, TB-500, semaglutide, tirzepatide, and any custom peptide.
Construction & Home
Concrete, gravel, fence posts, solar — built for contractors and homeowners.
Concrete Calculator
Calculate cubic yards, cubic meters, and 60 lb / 80 lb bag counts for slabs, footings, and columns. Includes 10% waste factor by default.
Fence Post Concrete
Get the right number of 60 lb or 80 lb bags per fence post hole. Sizes for 4×4, 6×6, and round posts at any depth.
Gravel & Fill Dirt
Convert area and depth into cubic yards and tons of gravel, fill dirt, sand, or topsoil. Handles density per material.
Solar Panel Savings
Estimate annual kWh production, lifetime savings, and payback period for a residential solar array. Customize by state sun hours and utility rate.
Education
GPA and grade tools that answer the question students actually ask.
Cumulative GPA
Calculate your true cumulative GPA across all semesters. Add prior cumulative GPA + credits, then this term's grades.
Weighted GPA
Calculate weighted high-school GPA. Toggle Honors (+0.5) and AP/IB (+1.0) bonuses on each course.
Final Grade
Find the exact score you need on your final exam to land your target overall grade. Supports custom final exam weight.
Developer Tools
Practical calculators for builders — token costs, latency, conversions.
AI Token Cost
Estimate the cost of an LLM workload. Plug in tokens-in, tokens-out, monthly volume, and get a per-call and monthly cost across major providers.
LLM Cost Optimizer
Paste your actual prompt + system prompt. We tokenize it, project monthly cost across GPT-4o, Claude, Gemini, and Llama at your volume, and recommend the cheapest model that meets your latency and capability bar.
Writers Tools
Manuscript formatting, ebook export, and writer-grade utilities for self-publishers.
File Converters
Privacy-first, in-browser converters. Your files never leave your device.
HEIC → JPG
Convert iPhone HEIC photos to JPG without uploading a single byte. Everything runs locally in your browser — your files never leave your device.
WebP → PNG
Convert WebP images to PNG without uploading. Pure browser conversion using the Canvas API — your files stay on your device.