Home

Anchor Calc — Free Online Calculators, Right in Your Browser
ANCHORCALC

Free Smart Calculators — right in your browser

Home projects, AP scores, mortgages, hydration, even your OSRS drop rate. 40+ checked calculators, built for U.S. units. No sign-up, no waiting.

Instant No upload No sign-up Free forever

Home & Yard

Cubic Yard

HOT

Mulch, gravel, dirt & concrete by the yard

Dirt Calculator

Topsoil and fill dirt for any bed or yard

Pool Salt

Exact bags needed for your target PPM

Recessed Lighting

Spacing and fixture count by room size

Gas Rate

NEW

Appliance gas consumption from meter readings

Boiler Feed Pump

Feed pump sizing and flow calculations

School

AP Lang Score

Estimate your 1–5 AP Lang exam score

APUSH Score

HOT

Estimate your AP US History score

AP World Score

Estimate your AP World History score

AP Stats Score

Estimate your AP Statistics score

Money

Mortgage

HOT

Monthly payment, interest & amortization

Rent

What you can afford based on income

Diminished Value

Vehicle value lost after an accident

Dental Implants Cost

Estimate total cost by implant count

Mortgage Calc Games

Interactive scenarios to test payoff strategies

Health & Fitness

Water Intake

Daily ounces by weight and activity level

PFT Calculator

Physical fitness test score by branch

AF PT Calculator

Air Force fitness test scoring by age & sex

Gaming

Pokémon Catch Rate

Catch odds by ball, HP & status

OSRS Dry Calculator

NEW

Odds of your current drought at any rate
How it works

Built to be right, not just fast

Anchor Calc isn’t one generic formula wearing 40 labels. Each calculator is built and checked against the standard method used in its own field, then tested against known example cases before it goes live.

Verified formulas

Sourced from official standards, not rough approximations.

U.S. units first

Feet, gallons, and dollars by default — metric shown where it helps.

Instant, in-browser

Your numbers never leave the page — results update as you type.

Kept current

Rates, brackets, and scoring tables are reviewed every year.

FAQ

Frequently asked questions

Are Anchor Calc’s calculators actually free?
Yes. Every calculator is free with no account, no paywall, and no email required to see your result.
Do I need to upload any files or data?
No. All calculations run instantly using the numbers you type in — nothing is uploaded or stored on a server.
Are the calculators built for U.S. units?
Yes — U.S. customary units are the default across the site, with metric shown where it’s genuinely useful.
How accurate are the results?
Each calculator is built against the standard formula used in its field and checked against known example cases before publishing.

Have a calculator idea we’re missing?

We add new calculators every week based on what people are actually searching for.

Suggest a calculator