ConvBolt — Unit ConverterOunces to Tonnes Converter
Converting ounces to tonnes is a multiplication by a fixed factor: 1 oz = 2.8350e-5 t. The table below covers the values people look up most often, and the formula section shows exactly where that factor comes from.
Because one ounce works out to 2.8350e-5 t, the tonne is the far smaller unit of the two: a figure given in tonne always carries a smaller number than the same measurement in ounce. A chart drawn in oz can hide that, so check which label the axis uses before you compare two readings.
Cooking and shipping are the two places this pair appears most: a kitchen scale reads in ounces while a recipe or label is written in tonnes, and a courier tariff built on tonnes still has to be checked against a scale showing ounces.
The conversion factor used here is 2.8350e-5 t per ounce (7 significant digits as shown). Kept to seven figures it covers professional measurement; if you round it to two or three decimals for a spreadsheet, the error scales with the input — at a value of 1,000 oz a factor rounded to three decimals can be off by a measurable amount. The reverse direction uses 35273.96 oz per t, the exact reciprocal, so a round trip through both pages returns your original number.
Ounces to Tonnes formula
Use this formula to convert any ounce value to tonnes:
Worked example: 100 oz × 2.8350e-5 = 0.002834952 t.
Ounces to Tonnes conversion table
| Ounces (oz) | Tonnes (t) |
|---|---|
| 0.5 oz | 1.4175e-5 t |
| 1 oz | 2.8350e-5 t |
| 2 oz | 5.6699e-5 t |
| 5 oz | 0.0001417476 t |
| 10 oz | 0.0002834952 t |
| 20 oz | 0.0005669905 t |
| 50 oz | 0.001417476 t |
| 100 oz | 0.002834952 t |
| 500 oz | 0.01417476 t |
| 1000 oz | 0.02834952 t |
How to convert ounces to tonnes
Multiply the ounce value by 2.8350e-5 to get the equivalent in tonnes. This single factor works for every value in the table above and for anything else you need — there is no per-value adjustment, which is why a conversion table and a calculator always agree.
If you need the opposite direction, use the Tonnes to Ounces converter instead of dividing by hand; both pages use the same source factors. For every other oz conversion in one place, see the oz conversion hub.
Frequently asked questions
How many tonnes are in 1 ounce?
1 ounce = 2.8350e-5 t.
What is 100 ounces in tonnes?
100 oz = 0.002834952 t.
Is converting ounces to tonnes the same as tonnes to ounces?
No — the direction changes the multiplier. The reverse conversion (1 t = 35273.96 oz) is on the Tonnes to Ounces page.
Related conversions
Try the ConvBolt Unit Converter for any other weight unit, browse the Weight conversions, or read our conversion guides.