What is bitumen content in asphalt?

Bitumen content (binder content) is the percentage of bitumen binder by weight in the total asphalt mix. Standard ranges: HMA surface course: 5.0–6.5%. HMA base course: 4.5–5.5%. SMA: 6.0–7.0%. Open-graded/OGFC: 5.5–7.0%. The bitumen percentage is determined by the mix design (Marshall or Superpave method) and specified in the job mix formula (JMF).

What is tack coat and how much bitumen does it need?

Tack coat is a thin bitumen emulsion spray applied between asphalt layers to ensure bonding. Standard application rate: 0.05–0.15 gallons per square yard (0.23–0.68 L/m²). For a normal milled surface: 0.08–0.10 gal/yd². For a very smooth or oxidised surface: 0.10–0.15 gal/yd². Missing or insufficient tack coat causes inter-layer delamination within 2–5 years.

What bitumen grade should I use?

US PG grading: PG 64-22 for most of the continental US (moderate climate). PG 70-22 or 76-22 for hot climates (Arizona, Texas, Florida). PG 58-28 for cold climates (Minnesota, Montana). PG 52-34 or 46-34 for very cold regions (Alaska, northern Canada). The first number is max pavement temperature resistance; the second (negative) is minimum temperature resistance.

How do you calculate tack coat bitumen quantity?

Tack coat quantity (gal) = Area (yd²) × Application rate (gal/yd²). Convert ft² to yd² by dividing by 9. Example: 50,000 ft² ÷ 9 = 5,556 yd². At 0.10 gal/yd²: 5,556 × 0.10 = 556 gallons of emulsion. Note: emulsions contain 60–70% bitumen — confirm residual binder content with your supplier.

🛢️ For engineers, specifiers & plant managers

Bitumen Calculator
Binder Quantity & Tack Coat

Calculate bitumen binder quantity in tons, kg, litres, and gallons from area, thickness, and binder content %. Includes a separate tack coat and prime coat estimator. Imperial and metric units.

Area (sq ft)

ft²

HMA thickness (inches)

HMA mix type sets density

Binder specification

Binder content % by weight of mix

Surface course: 5.0–6.5% · Base course: 4.5–5.5% · SMA: 6.0–7.0% · OGFC: 5.5–7.0%

Waste / over-order 5%

0%5% standard15%

Bitumen price optional — activates cost

$/ton

Bitumen binder (asphalt cement) costs ~$400–$700/ton in 2026. Not the same as HMA plant price.

Bitumen Results By weight & volume

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Enter area, thickness, and binder content % to calculate bitumen quantity in tons, kg, litres, and gallons.

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Tack Coat & Prime Coat Calculator

Separate from HMA binder — calculate emulsion for inter-layer bonding

Surface area (sq ft)

ft²

Application rate gal/yd²

gal/yd²

Application type

Rate pre-fills on type selection. Override manually if your specification differs.

Emulsion residual content % — check supplier data sheet

Typical cationic emulsion: 60–70% residual. CSS-1h: 57–62%. Enter 100% if using neat (uncut) bitumen.

Tack / Prime Results Emulsion quantity

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Enter area and select application type to calculate emulsion quantity.

The calculation explained

How to calculate bitumen quantity — formula and examples

Bitumen calculation is two steps: first calculate total HMA tonnage, then extract the binder fraction using the specified binder content percentage.

Binder (t) = ( Area_ft² × D_in ÷ 12 × 145 ÷ 2,000 ) × BC% ÷ 100

Step 1 — HMA tonnage: (Area × Depth_in ÷ 12 × 145) ÷ 2,000
Step 2 — Binder: HMA tons × (Binder content % ÷ 100)

Area (ft²)

Total paving area. Use L×W mode to enter dimensions directly.

D ÷ 12

Depth in inches converted to feet. Compacted in-place depth.

145 lb/ft³

HMA density. Changes with mix type — selected automatically.

BC% (4.5–7%)

Binder content from job mix formula (JMF). Confirm with plant QC.

Worked example — road project

10,000 ft² wearing course at 2 inches, HMA at 145 lb/ft³, 5.5% binder content, 5% waste.

Calculate HMA volume

10,000 ft² × (2 ÷ 12) ft = 1,666.7 ft³

Convert to tons

1,666.7 × 145 lb/ft³ = 241,667 lb ÷ 2,000 = 120.8 tons HMA

Extract binder fraction

120.8 × 5.5% = 6.64 tons binder base quantity

Add waste & convert

6.64 × 1.05 = 6.97 tons to order
= 6,768 litres / 1,788 US gallons

⚠️ The mistake that cost one contractor $75,000

A civil engineer calculated asphalt mix quantity perfectly for a 5 km highway project. Then ordered bitumen based on mix tonnage × 5%. What he forgot: prime coat and tack coat require entirely separate bitumen quantities that are not part of the HMA binder calculation.

He ordered 500 tons of bitumen. He needed 650 tons. The plant was 200 miles away. Emergency delivery fees: $75,000.

Use the Tack Coat Calculator above — it is completely separate from the HMA binder calculation. Always calculate them independently and sum the totals.

The three grading systems explained

Bitumen grades — PG, penetration, and viscosity

Three grading systems are used globally. The right grade for your project depends on climate, traffic load, and layer position. Using the wrong grade causes early pavement failure.

US Standard (AASHTO M 320)

Performance Grade (PG)

Format: PG HH-LL where HH = max pavement temp (°C) and LL = min temp. PG 64-22 means performs up to 64°C and down to −22°C.

PG 52-34 / 46-34Very cold (Alaska, N. Canada)

PG 58-28Cold climates (MN, MT, ME)

PG 64-22Most of continental US ⭐

PG 70-22 / 76-22Hot climates (AZ, TX, FL)

International standard (BS/EN)

Penetration Grade

Graded by depth (in 0.1 mm) a needle penetrates at 25°C. Higher number = softer bitumen. Most widely used in UK, Europe, Middle East, and South Asia.

20/30 penVery stiff — industrial

40/60 penStiff — hot climates, HVS

60/70 penStandard highway ⭐

80/100 penTemperate / cool climates

160/220 penCold climates, soft areas

India / South Asia (IS 73:2013)

Viscosity Grade (VG)

Graded by viscosity at 60°C in decapoise. Higher number = stiffer. Replaced penetration grading in India in 2006 per IS standard.

VG-10Cold climates, prime coat, tack coat

VG-20Cold / high altitude regions

VG-30Standard highway grade ⭐

VG-40Extreme heat, heavy traffic

Binder content by mix type — reference table

These are the ranges from published mix design specifications. The exact value for your project comes from the Job Mix Formula (JMF). Always confirm with your plant QC before ordering.

Mix type	Binder content %	Typical PG grade (US)	Typical pen grade (intl)	Use case
HMA surface course Wearing layer	5.0–6.5%	PG 64-22 / 70-22	60/70 pen	Top layer — roads, driveways, parking lots
HMA binder course Intermediate layer	4.5–5.5%	PG 58-28 / 64-22	60/70 or 80/100 pen	Structural intermediate layer under surface course
HMA base course Bottom layer	4.0–5.0%	PG 58-28	80/100 pen	Primary load-bearing layer on heavy-duty roads
Stone Matrix (SMA) High-performance	6.0–7.0%	PG 76-22 / PMB	PMB / 40/60 pen	High-stress highways, intersections, bus lanes
Open-Graded / OGFC Porous, permeable	5.5–7.0%	PMB / rubber modified	PMB	Drainage, noise reduction, airport surfaces
Warm Mix (WMA) Lower temperature	5.0–6.5%	Same as HMA	Same as HMA	Eco-friendly alternative to HMA — same quantities

Bitumen binder density

1.03

t/m³ (1,030 kg/m³)

Used to convert binder mass to volume for tank ordering and sprayer scheduling. Pure binder — not the mixed HMA.

HMA density (compacted)

145

lb/ft³ (2,322 kg/m³)

Standard HMA at 145 lb/ft³ used for total mix tonnage calculation. Varies by mix design — confirm with plant.

Tack coat (typical)

0.08–0.12

gal/yd² emulsion

Inter-layer bonding. Verify emulsion residual content (typically 60–70%) to get net binder quantity.

The most overlooked bitumen calculation

Tack coat, prime coat & surface treatment — rates & quantities

These applications use bitumen independently from HMA binder. They must be calculated and ordered separately. Forgetting them is one of the most expensive mistakes in paving project management.

Application	Rate (gal/yd²)	Rate (L/m²)	Material	When to use
Tack coat — milled surface	0.05–0.08	0.23–0.36	CRS-1h, CSS-1h emulsion	Fresh-milled or new HMA surface before next lift
Tack coat — existing surface	0.08–0.10	0.36–0.45	CRS-1h, CSS-1h emulsion	Standard oxidised/aged asphalt surface
Tack coat — smooth/polished	0.10–0.15	0.45–0.68	CRS-2 or neat bitumen	Very smooth, glazed, or non-porous surface
Prime coat — open granular base	0.25–0.40	1.13–1.81	MC-70 cutback or emulsion	Granular base before first HMA lift
Prime coat — dense granular base	0.40–0.60	1.81–2.72	MC-70 or CSS-1 emulsion	Dense, low-voids granular base
Chip seal / surface dressing	1.0–1.8	4.5–8.1	Neat bitumen or emulsion	Wearing course treatment — low-traffic roads
Slurry seal	—	—	Bitumen emulsion + fine aggregate	Preventive maintenance — sealing surface micro-cracks

Critical note on emulsion residual content: Tack coat rates are given in total emulsion volume, not net bitumen volume. A CSS-1h emulsion at 62% residual means only 62% of the volume you spray is actual bitumen — the remaining 38% is water that evaporates. When ordering bitumen for emulsion production, multiply the emulsion volume by the residual content to get net binder required.

Technical fundamentals

What is bitumen? Bitumen vs asphalt — key differences

The two terms are used interchangeably in everyday language — but for calculation purposes, the distinction is critical. Mixing them up leads directly to ordering errors.

Bitumen (asphalt cement / binder)

The binder — 4.5–7% of HMA by weight

•Black, viscous, petroleum-derived material
•Produced by vacuum distillation of crude oil
•Density: ~1.03 t/m³ (1,030 kg/m³)
•Price: ~$400–$700/ton (2026 US market)
•Graded by PG, penetration, or viscosity system
•What this calculator computes

Asphalt / HMA (hot mix asphalt)

The finished mix — 100% of paving material

•Bitumen binder + aggregate + filler
•Aggregate = 93–95.5% of total weight
•HMA density: ~145 lb/ft³ (2,322 kg/m³)
•Plant price: $80–$160/ton (aggregate cheap)
•Mixed at ~300°F, placed at 275–325°F
•What the Tonnage Calculator computes

Why the distinction matters for ordering: HMA costs $80–$160/ton because aggregate (95% of the mix) is cheap. Bitumen binder costs $400–$700/ton. When your plant gives you a total HMA price, the binder cost is embedded in it. When ordering bitumen separately (for tack coat, prime coat, or plant-only supply), you are ordering at the much higher pure binder price. Never mix up the two price points — the mistake can inflate your material budget by 3–5×.

Technical questions answered

Bitumen calculator — FAQ

Every common question from engineers, specifiers, and plant managers — answered with exact numbers.

How do you calculate bitumen quantity for a road project?+

Two-step process: Step 1 — HMA tonnage: (Area ft² × Depth_in ÷ 12 × 145) ÷ 2,000. Step 2 — Binder: HMA tons × (Binder content % ÷ 100). Example: 10,000 ft² at 2", 5.5% binder = 120.8 tons HMA × 0.055 = 6.64 tons binder base. Add 5% waste = 6.97 tons to order. Use the calculator above for any dimensions in both imperial and metric.

What is the difference between bitumen and asphalt?+

Bitumen is the petroleum-derived binder — the black, viscous glue that makes up 4.5–7% of HMA by weight. Asphalt (HMA) is the complete paving mix: bitumen + aggregate + filler. The HMA plant price ($80–$160/ton) is much lower than pure bitumen binder price ($400–$700/ton) because aggregate (94%+ of the mix) is cheap. Always clarify which one you're pricing when getting quotes.

What is the standard binder content for HMA?+

Surface (wearing) course: 5.0–6.5% by weight. Binder course (intermediate): 4.5–5.5%. Base course: 4.0–5.0%. Stone Matrix Asphalt (SMA): 6.0–7.0%. Open-graded/OGFC: 5.5–7.0%. The exact value for your project is specified in the Job Mix Formula (JMF) from the plant's mix design. Always confirm with plant QC before ordering — design vs actual can vary by ±0.3%.

How do I calculate tack coat bitumen quantity?+

Tack coat quantity (gal) = Area (yd²) × Application rate (gal/yd²). Convert ft² to yd² by dividing by 9. Example: 50,000 ft² ÷ 9 = 5,556 yd². At 0.10 gal/yd² = 556 gallons of emulsion. Important: emulsion is 60–70% bitumen — to get net binder, multiply by residual content: 556 × 0.65 = 361 gallons of net binder. Use the Tack Coat Calculator above for all conversions automatically.

What PG grade bitumen should I specify?+

Use AASHTO LTPP Bind software or your state DOT specification for the exact recommendation. General guidance: PG 64-22 for most of the continental US. PG 70-22 or 76-22 for hot climates (AZ, TX, FL, CA interior). PG 58-28 for cold climates (MN, WI, MT, CO mountain). PG 52-34 for severe cold (ND, northern MN, Alaska). For high-traffic applications, move one grade higher than the climate recommendation.

What is the density of bitumen for volume calculation?+

Pure bitumen binder density: 1.03 t/m³ (1,030 kg/m³ or 64.3 lb/ft³). This converts binder mass to volume for tank ordering and sprayer scheduling. Note: this is the binder density, not the HMA mix density (145 lb/ft³ / 2,322 kg/m³). 1 ton of bitumen = 1,000 kg ÷ 1.03 = 971 litres = 256 US gallons.

Why is too much bitumen bad for asphalt?+

Excess bitumen fills the air voids in the mix, reducing stability. When the mix gets hot under traffic, the excess binder bleeds to the surface (called bleeding or flushing) — creating a slick, sticky surface that reduces skid resistance and attracts more aggregate. Optimum bitumen content (OBC) is determined by Marshall or Superpave mix design to balance stability, durability, and void content. Too little bitumen is also bad — it leaves the mix too rigid and brittle, prone to ravelling and fatigue cracking.

How much does bitumen cost per ton in 2026?+

Pure bitumen binder (asphalt cement, AC) costs approximately $400–$700/ton in the US in 2026, tracking crude oil prices with a 2–3 month lag. This is the binder cost within HMA — not the same as the HMA plant price ($80–$160/ton), which dilutes the binder cost across the 93%+ aggregate fraction.

What is the filler-to-bitumen ratio?+

The filler-bitumen ratio (F/B) = Mineral filler % ÷ Bitumen content %. Most specifications require F/B to fall between 0.6 and 1.2. Too high (>1.2) produces a stiff, brittle mix prone to cracking. Too low (<0.6) reduces cohesion and mix stability. Example: 6% filler ÷ 5.5% binder = 1.09 — within spec. This ratio is checked during mix design but should be verified after any change to filler or binder content.

Can I use metric units with this calculator?+

Yes — click Metric (m² / mm) in the unit toggle at the top of the calculator. The calculator switches all inputs to square metres and millimetres, and outputs to metric tonnes, kilograms, and litres. The formula adjusts: HMA (t) = (Area_m² × Depth_mm ÷ 1000 × 2,322 kg/m³) ÷ 1,000. The tack coat calculator also adjusts to L/m² output.

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