Convert US barrel to US oil barrel
Unit definitions
US barrel
The US barrel is the standard liquid barrel in the US customary system. One US barrel equals $31.5$ US liquid gallons.
US oil barrel
The US oil barrel is defined as exactly $42$ US liquid gallons. It is used for measuring crude oil and other petroleum products.
How to convert US barrel to US oil barrel
$$\text{Volume}_{\text{bbl (oil)}} = \text{Volume}_{\text{bbl (US)}} \cdot 0.75$$
Examples
Example 1
Convert $50.0\ \text{bbl (US)}$ to $\text{bbl (oil)}$.
$$\text{Volume}_{\text{bbl (oil)}} = 50.0 \cdot 0.75$$
$$\text{Volume}_{\text{bbl (oil)}} = 37.5$$
$$\therefore \ 50.0\ \text{bbl (US)} = 37.5 \ \text{bbl (oil)}$$
Example 2
Convert $85.0\ \text{bbl (US)}$ to $\text{bbl (oil)}$.
$$\text{Volume}_{\text{bbl (oil)}} = 85.0 \cdot 0.75$$
$$\text{Volume}_{\text{bbl (oil)}} = 63.75$$
$$\therefore \ 85.0\ \text{bbl (US)} = 63.75 \ \text{bbl (oil)}$$
Example 3
Convert $120.0\ \text{bbl (US)}$ to $\text{bbl (oil)}$.
$$\text{Volume}_{\text{bbl (oil)}} = 120.0 \cdot 0.75$$
$$\text{Volume}_{\text{bbl (oil)}} = 90$$
$$\therefore \ 120.0\ \text{bbl (US)} = 90 \ \text{bbl (oil)}$$
Example 4
Convert $150.0\ \text{bbl (US)}$ to $\text{bbl (oil)}$.
$$\text{Volume}_{\text{bbl (oil)}} = 150.0 \cdot 0.75$$
$$\text{Volume}_{\text{bbl (oil)}} = 112.5$$
$$\therefore \ 150.0\ \text{bbl (US)} = 112.5 \ \text{bbl (oil)}$$
Example 5
Convert $160.0\ \text{bbl (US)}$ to $\text{bbl (oil)}$.
$$\text{Volume}_{\text{bbl (oil)}} = 160.0 \cdot 0.75$$
$$\text{Volume}_{\text{bbl (oil)}} = 120$$
$$\therefore \ 160.0\ \text{bbl (US)} = 120 \ \text{bbl (oil)}$$