About this site

MyConstructionCalc is a set of free construction and civil engineering calculators. It exists because most quantity calculations on site are simple arithmetic that is easy to get wrong under time pressure, and because most online calculators hide the assumptions that actually determine the answer.

How these calculators are built

Every tool here follows the same rules:

• The formula is published. Each page shows the calculation it performs, step by step, so you can verify it by hand.
• Material properties are inputs, not constants. Densities, mix ratios and coverage rates change from project to project. They are editable everywhere they appear, with the default clearly labelled as a typical value rather than a correct one.
• Wastage is visible. Allowances are separate, adjustable inputs, so you can see exactly how much of the answer is material and how much is contingency.
• Nothing is invented. Where a value depends on a specification, a laboratory result or a supplier data sheet, the page says so rather than substituting a plausible-looking number.

Who writes it

The site is written and maintained by one person, writing as Ethan Mercer: a QA/QC engineer with a BSc in Civil Engineering, working in road construction since 2011 on highway, intercity, internal and maintenance road projects in the Gulf, to roads authority and municipality specifications. The daily work is materials testing and site quality control — soil and subgrade, aggregates, and asphalt from plant production through laydown to core results.

Ethan Mercer is a pen name. The experience, the projects and the figures behind the guides are real; the name is not the one on the passport.

Guides on this site are written from that work rather than assembled from other websites. Where a figure is a typical range rather than a rule, it says so.

Who it is for

Site engineers, quantity surveyors, foremen, technicians, students and anyone estimating materials for construction work. The tools are written to be usable on a phone in daylight, because that is where most of these calculations actually get done.

What it is not

These are quantity and conversion tools. They do not perform structural design, they do not size members, and they do not check compliance with any building code. Design decisions belong to a qualified engineer working to the standards that apply in your jurisdiction.

Corrections

Every calculator is checked against worked examples and an automated test suite before it goes live, and the formulas are published on each page so you can verify them yourself. Where a figure is a typical range rather than a fixed value, the page says so. Accuracy matters more here than completeness.