Dose rate at 1 m from a given Transport Index (TI)
This calculator estimates the radiation dose rate at 1 metre from a package based on a specified Transport Index (TI).
It provides the inverse of the standard TI determination method and is useful when reviewing transport documents, planning work around packages with known TI values, or sense-checking stated transport hazards.
What this calculator does
The Transport Index is defined by the relationship between the dose rate at 1 m and a scaling factor of 100. This calculator reverses that relationship:
Once the dose rate at 1 m is determined in mSv/hr, the result can be converted into a range of commonly used SI and legacy dose-rate units.
Supported output units
The estimated dose rate at 1 m can be displayed in:
nanosieverts per hour (nSv/hr)
microsieverts per hour (µSv/hr)
millisieverts per hour (mSv/hr)
sieverts per hour (Sv/hr)
microrem per hour (µrem/hr)
millirem per hour (mrem/hr)
rem per hour (rem/hr)
Using this result
The calculated dose rate represents the maximum external radiation level at 1 m that would be consistent with the specified TI.
If you need to estimate dose rates at other distances from the package, you can use the linked Inverse square law – dose rate at a new distance calculator, noting that inverse-square behaviour is an approximation and may not apply close to extended or heavily shielded sources.
Important notes and limitations
This calculator provides an estimate based on the regulatory definition of TI.
Actual dose rates should always be confirmed by direct measurement using appropriate instrumentation.
Where multiple radiation types contribute to the external hazard, the stated TI may represent a combined value rather than a single measured gamma or neutron dose rate.
As with all transport planning tools, this calculator does not replace professional judgement, local procedures, or regulatory compliance checks.