Browser-based calculator platform
Precise calculators for decisions that matter
Calcafy offers 12 free calculators across math, construction, finance, and date & time — with transparent formulas, clear assumptions, and no account required.
- Fast, local calculations
- Transparent formulas
- Mobile-friendly tools
Find a calculator
Search by calculator name, category, or common keyword.
Featured calculators
Common starting points across finance, math, construction, and everyday calculations.
Percentage Calculator
Percentages, changes, time/mass ratios, and OBP
Proportion Calculator
Solve a/b = c/d with cross-multiplication
Cubic Yard Calculator
Volume in cubic yards for common shapes
Loan Payment Calculator
Monthly payment, amortization, and extra payment estimates
Compound Interest Calculator
Savings and investment growth projections
Date Difference Calculator
Days between two dates
Concrete Calculator
Concrete volume and bag estimates
Square Footage Calculator
Area for common shapes
Age Calculator
Calendar age and age difference
Business Days Calculator
Working days with holiday options
Simple Interest Calculator
Simple interest and reverse solving
Explore by category
Browse calculators grouped by topic. Three category hubs are available now; additional topics will be added as more tools are published.
Math & Algebra
Fractions, proportions, matrices, and percentages
4 calculators
Construction & Materials
Area, volume, concrete, gravel, lumber, and roofing
8 calculators
Finance
Loans, savings growth, and dividend tools
4 calculators
Date & Time
Age, dates, business days, and duration math
5 calculators