Jimmy

About

I am a civil and software engineer based in New York, and I run BitumenCalc under Big Techies. The site is a one-person project: I build the calculators, write the articles, choose the default values and answer the email.

It began as a spreadsheet I kept rebuilding. Estimating asphalt means juggling area in one unit, thickness in another and a density from a mix sheet in a third, then converting to whatever ton the supplier invoices in. The arithmetic is simple; doing it correctly under deadline, four conversions deep, is where it goes wrong. Working across civil engineering and software made putting it on the web the obvious fix.

What I write about here

Quantity estimation, mostly: densities and where they come from, binder content, tack and prime coat spray rates, RAP, mix designations and how they differ between road authorities. The recurring theme is unit discipline, because that is what actually causes short orders.

How I work

Default values come from published specifications and from the Asphalt Institute's MS-2, and every technical page links the document it drew from. Figures are checked against the source, against the same quantity in the other unit system, and against the other pages on this site that quote them.

That last check found a real error in July 2026: five US state pages were using 110 lb/ft³ as a density when the figure is really 110 lb per square yard per inch, which understated tonnage by roughly 24%. It is documented in the editorial policy rather than quietly patched, because a site that never publishes a correction is a site that is not checking.

Everything I have written here

Fourteen pieces, all published March 2026 and last reviewed July 2026. They are listed here with what each one is actually for, because the titles alone do not always make that obvious.

• Asphalt Thickness Guide
  What actually drives layer depth — traffic, subgrade, and why a driveway and a haul road are different problems.
• Asphalt Tonnage Guide
  Unit conversion and waste factors in longhand, for checking a number before you commit to it.
• Asphalt Driveway Costs
  Where the money goes on a domestic job beyond the mix itself.
• Recycled Asphalt Millings
  Compaction ratios and coverage for RAP, and where reclaimed material is not appropriate.
• Prime Coat vs Tack Coat
  Two products that get confused constantly. What each one bonds, and when.
• Tack Coat Rates
  Residual rates, dilution, and why the drum figure is not the applied figure.
• Tons per Cubic Yard
  The conversion that causes the most short orders in US estimating.
• How Much Asphalt Do I Need
  A full estimate from scratch, assuming no prior knowledge of mix types.
• Asphalt Density Guide
  Typical ranges in kg/m³, lb/ft³ and t/m³, and where each figure comes from.
• Bitumen Content
  How much binder is in a mix, and why that percentage drives the price.
• Bitumen Quantity for Roads
  Working from a road cross-section rather than a rectangle.
• Chip Seal Spray Rates
  Sprayed seals are measured by rate over area, not by volume. Why that matters.
• Bitumen Density & Cargo Volume
  Temperature correction for bulk bitumen in transit and storage.
• Modified Bitumen Roofing
  Roofing membrane rather than pavement — different units, different failure modes.

What I get wrong

Worth stating plainly, since every other author page on the internet claims the opposite. The July 2026 density error described above sat on five pages for months before the cross-check caught it. It was not subtle — a 24% shortfall on every worked example — and nobody reported it, which tells me most visitors use the calculator and skip the prose.

So: the calculator engine is the part I trust most, because it is one code path exercised by every page and it works in SI units throughout. The prose examples are the part most likely to contain a slip. If a worked example on this site disagrees with the calculator on the same page, the calculator is right and I want to hear about it.

What I do not do

I do not do pavement design here, and nothing on this site should be read as one. I am not producing stamped drawings, I have not seen your subgrade, and thickness selection needs both. These are estimating tools. The disclaimer sets out the boundary properly.

Corrections and contact

If a number here is wrong, email info@bitumencalc.com with the page, the figure and what you believe it should be. I reply within two working days, and a specific report gets fixed fastest.

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