Whisky OLA vs. RLA Value Calculator

Understand How Your Cask Has matured

Easily compare the original litres of alcohol (OLA) you purchased with the regauged litres of alcohol (RLA) to see your cask’s actual value (per litre) and any loss due to evaporation from your whisky cask.

What is the difference between OLA and RLA?

OLA – Original Litres of Alcohol

Original alcohol content in litres at the time of purchase.

RLA – Regauged Litres of Alcohol

What is a regauge? A regauge is the process of remeasuring a whisky cask to determine how much alcohol remains after maturation. As the cask ages, it naturally loses volume through evaporation – known as the angel’s share – and the alcohol strength (ABV) often drops too. This means the cask no longer contains its original litres of alcohol (OLA), but a reduced volume known as regauged litres of alcohol (RLA).

Enter Your Cask Details:

  • The general trend in Scotland is that the Angel’s Share – the annual loss of whisky through cask evaporation – is typically around 2% to 3% of volume. Over the same period the ABV (alcohol by volume) also declines, usually by around 0.5% per year, as a rough guideline
  • This is not a direct reflection of current market value, but a conversion from OLA to RLA. This is because RLA provides a more accurate and risk-adjusted measure of the cask’s true specifics, and so the price includes an uplift to reflect this added value.

Why This Matters

  • This tool helps cask owners understand how evaporation (the “angel’s share”) affects the value of their investment.
  • By comparing OLA to RLA, cask owners can make informed decisions on when to bottle, sell, or hold a cask.