Unit conversions (e.g. tonne → litre for fuel)

In some industries—particularly oil, gas, and fuel distribution—products are bought and sold in different units. For example, you might purchase diesel in tonnes but sell it to customers in litres. Unit conversions let you define a conversion ratio between two units so that Usystems automatically calculates the quantity when you switch units on a purchase order, invoice, or stock receipt.

Before you start

• You must have admin or inventory manager permissions to set up unit conversions.
• The product must already exist in your product catalog.
• Identify the two units you need to convert (e.g., tonne and litre).
• Know the conversion factor (e.g., 1 tonne of diesel = approximately 1,190 litres, depending on density).
• Unit conversions apply per product; different products may have different conversion ratios.

Steps

1. Go to Products & Services → Products Open in Usystems.
2. Search for or select the product you want to set up a unit conversion for.
3. Open the product detail page and locate the Units or Unit conversions section.
4. Click Add conversion or + New conversion.
5. Choose the From unit (e.g., tonne) and the To unit (e.g., litre).
6. Enter the Conversion factor — the amount of the "to" unit that equals one "from" unit. For example, enter 1190 if 1 tonne = 1190 litres.
7. Click Save or Create.
8. The conversion is now active. When you create a purchase order, invoice, or receipt, you can switch between units and the system will auto-calculate the quantity.

Tips & common mistakes

• Verify the conversion factor with your supplier — density and specific gravity vary; confirm the exact ratio for your product.
• Test the conversion before bulk use — create a small test purchase order or receipt and verify that the quantity converts correctly.
• One conversion ratio per unit pair — you cannot have multiple conversion factors for the same unit pair on one product. If you need different ratios (e.g., seasonal density changes), note the average or consult with your supplier.
• Units must exist in the system — if the unit (e.g., "litre" or "tonne") is not yet in your system, create it under Products & Services → Units before setting up the conversion.
• Conversions apply during entry, not after — if you enter a quantity in one unit, switching to another unit will recalculate. But once saved, the document stores the entered unit; changing units on a saved document does not automatically recalculate historical records.