Free calculators
Instant, client-side tools — no signupQuick estimators for roof snow load, loan payoff, square footage, BMI, and open-burning rules by ZIP. Results are educational estimates only.
Magnitude and energy
Two magnitudes → amplitude ratio and energy ratio, using the USGS whole-step rule.
Distance to fault references
Kilometers to USGS epicenters, Smithsonian volcanoes, and Ring of Fire rectangles.
VEI explorer
VEI 0–8 with the examples and volume anchors USGS publishes.
Roof snow load
Estimate design roof snow load (psf) from ZIP, pitch, and exposure.
Loan payoff / APR
Payoff time, total interest, and amortization from principal and APR.
Square footage
Add rooms (length × width) for a quick floor-area total.
BMI calculator
Height and weight → BMI with CDC adult category labels.
Can I burn this?
ZIP + material → likely allowed, permit, or prohibited (verify locally).
Disclaimer: These tools provide rough estimates for education and planning conversations. They are not engineering, legal, medical, financial, or fire-authority advice. Always confirm with licensed professionals and local officials.