Free calculators, no account
Free calculators, and the math behind them
Every tool shows its formula, its units, and where the answer stops being useful.
Quick check: volume of a cylinder
The same arithmetic as the full tool, which also covers cones, spheres and other units.
Open the cylinder volume calculatorWhat each calculator page tells you
The pages are written to be checked rather than trusted. Open any tool on this site and you find the same four things.
- The formula, written out
- Not only the result. Each page states the equation it runs, so you can follow the steps by hand or move them into a spreadsheet.
- Units on every input
- Centimetres or inches, kilograms or pounds, litres or gallons. Every field names the unit it expects, so a conversion never happens by accident.
- A worked example
- A filled-in example you can compare against your own numbers before you rely on the output.
- Where the estimate stops
- Each page lists the assumptions it makes and what it leaves out, including the costs and conditions it cannot see.
Start with something practical
Six tools that get opened most often.
Cement Bag Calculator
Volume for a slab or footing, converted into the number of bags to buy.
Decimal to Fraction Calculator
Terminating, repeating, negative and mixed decimals, with the working shown.
CRC Calculator
Checksum values for the CRC polynomials that turn up in serial protocols.
Bolt Pattern Finder
Measure a wheel and identify the bolt pattern before ordering replacements.
Crown Molding Angle Calculator
The two mitre angles for any corner, spring angle included.
Baking Ingredient Converter
Cups, grams and ounces across the usual baking ingredients.
Browse by what you are working on
Eight groups, all free, no sign-in.
Building and remodelling
- Cement Bag Calculator
- Drywall Calculator
- Crown Molding Angle Calculator
- Exterior Paint Coverage Estimator
- Stair Stringer Calculator
Science and engineering
- Force Calculator
- Friction Calculator
- Density Calculator
- Molecular Weight Calculator
- Empirical Formula Calculator
Numbers and math
- Decimal to Fraction Calculator
- Factorial Calculator
- Base Converter
- Mean Median Mode Calculator
- Modulo Calculator
Computers and electronics
- CRC Calculator
- Download Time Calculator
- Battery Life Calculator
- PPI Calculator
- Server Capacity Calculator
Kitchen and cooking
- Baking Ingredient Converter
- Cup to Gram Calculator
- Air Fryer Conversion Calculator
- Coffee Brewing Calculator
- Cooking Time Calculator
Garden and smallholding
- NPK Ratio Calculator
- Drip Irrigation Layout Estimator
- Plant Population Calculator
- Compost C:N Ratio Calculator
- Cover Crop Seeding Rate Calculator
Guides that show the arithmetic
Longer pieces that work through a calculation end to end.
How to Calculate Cylinder Volume: A Practical Handbook for Real Projects
A handbook for tanks, pipes and containers, with the formula rearranged for each unknown.
Read the guideHow to Calculate Friction: A Field-Tested Guide for Real-World Forces
GuideHow Many Cement Bags for a Slab: My Field-Tested Cheat Sheet and Cost Comparison
GuideHow to Calculate Crown Molding Angle: A Visual Beginner’s Guide with Cheat Sheets
GuideHow to Make Pasta Dough Ratio Work at Any Scale: A Practitioner’s Master Formula
GuideHow to Calculate CRC Checksum by Hand: A Practitioner’s Guide to Manual CRC and Checksum Math
GuideWho runs Hive Point
Hive Point is a small, independently run site. The calculators and the guides are written and maintained by Ellis Vaughn, and pages are revisited when a formula, a unit convention or a published rate changes.
If a result looks wrong, send the inputs you used and the number you expected. Corrections are the most useful messages this site receives.
ContactWhat this site does not do
- It does not give financial, legal, medical or tax advice, and using it creates no professional relationship of any kind.
- It does not verify the numbers you type in. The output is arithmetic on your inputs, and it is only as good as they are.
- It does not replace someone who can look at your actual circumstances before you commit to a decision.
Questions people ask
No. Every tool runs in the browser, nothing is saved, and there is no sign-up step.
The arithmetic is exact for the numbers you enter. The inputs are the weak link: if a measurement, a rate or a pre-filled default is wrong, the result is wrong in the same proportion. Each page names the defaults it pre-fills.
Yes, with the inputs recorded next to them. The results are estimates, not appraisals or offers, and no lender, authority or supplier is bound by them.
Send the page, the inputs you used and the number you expected. Corrections are read first.
Building, science, maths, computing, cooking, garden, car and craft tools are collected in the sections on this page. Loan, tax, investment and legal estimators also exist on the site in their own sections, and they carry the same limit: arithmetic on your inputs, not advice.