

3 Facts about BriCal
- The BriCal was invented to quickly calculate pre-decimal British currency up to £500.
- This popular British calculator came in many different configurations for different maximum results and currencies.
- There are 12 pence in a shilling and 20 shilling in a pound, which make quick currency calculations difficult without a BriCal.
BriCal History
BriCal (after British Calculator) is a circular brass calculator, patented in 1905 by the engineer Herbert Dickinson and his wife, Mabel Dickinson. The adding machine was manufactured by the company British Calculators Ltd, London, from 1905 till the 1920s in different variants. The most common is a disk, with a diameter of 135 mm and thickness of 10 mm, weighing 450 g, put in a special case with velvet.
The exact time the company ended is unknown. It appears most of the BriCal calculating machines were manufactured in the first 10 to 20 years. Other sources cite manufacturing lasting until the 1950s.
Quick Facts
- Created
- 1905
- Creator
- Herbert Dickinson, Mabel Dickinson
- Original Use
- Performing calculations in British currency
- Cost
- £3, 3 shillings

BriCal: How It Worked
This particular British calculator machine has three or more concentric brass discs which are drawn clockwise with the stylus to add pounds, shillings, and pence. Using the pin or stylus, one rotates the chain, until the wanted sums show in the window of the adding machine. Sums can be calculated in pre-decimal currency up to £500.
In order to clear the calculator, it surprising takes a few steps. It does seem odd to have to take so much time for a tool that is saving time calculating. One has to notice where a red dot is on some of the teeth and then pull those teeth to zero using the stylus. Next, you have to do the same for the other two rings that are left. Finally, the counter wheel must be reset to zero by using the tiny knob. If all these steps are preformed, a user can move on to the next computation.
These are just the basic instructions for the original BriCal. The machine was manufactured in a surprising number of variants for its apparently short production time.
Some BriCal machines were manufactured to work with different currencies. Others could calculate sums over £500. Still others were designed in different sizes and colors.
BriCal: Historical Significance
According to the BriCal money calculating machine instruction booklet, this machine is capable of calculating British currency six times as fast as mental addition. While the machine appears to have been popular during its time, it was discontinued sometime in the 20th century. Some report it was only in production for approximately 10 to 20 years, with manufacturing ceasing some time before 1925. Others claim it was manufactured until 1950.
Up Next…
Want to find out more about calculators and their origins? See these reads below!
- Mechanical Calculators. It’s fascinating to see how calculators worked without power.
- Pascaline Calculator Explained — Everything You Need To Know. It actually does multiplication and division by repeating addition and subtraction.
- The History of Calculating Tools. We go way back and dig into the past of calculators.