Radiation Units Conversion Calculator

Version 2: Supporting information

With established search engines and AI being the latest thing,  a radiation (protection) unit conversion calculator might be assumed to be a dated concept. However, like our radiation protection links, we think a range of curated resources (including this calculator) are still great value.

The calculator is self explanatory, but here is a general breakdown.

• Select quantity type from the first dropdown menu (e.g. activity, dose, dose rate, shielding etc).
• With scientific notation off the calculator will try and display conventionally (e.g. 0.001 Gy/h) until a point is reached where it will force scientific notation (e.g. 1.000e^-6 Gy/h). With this option switched on it will display scientific notation at all times (e.g 1.000e^-3 Gy/h)
• Enter value is checked for validity (e.g. no negative numbers allowed), and contextual magnitude (i.e. attenuation is <1).
• The From unit and To unit set the desired conversion (for units available,  as set by the quantity drop down).
• Convert outputs the conversion which is displayed below the button. This needs to be clicked each time any changes are made to the calculator parameters.
• Swap Units  - a quick way of flipping the conversion on its head. 

Usage notes

Below are some clarifications which the user should be aware of when using this calculator.

Dose / Dose Rate. In these groups we have included the Gy, Rad, Sv and Rem. Where as 1 Gy = 0.01 Rad, and 1 Sv = 0.01 Rem, ordinarily 1 Gy ≠ 1Sv since one is absorbed dose, the other is equivalent  / effective dose. However in many cases, potential or actual exposures will be whole body from external sources of ionising radiation (often x-ray or gamma rays). Where both the radiation weighting fact is 1, and the tissue weighting factors sum to 1 (i.e. whole body), then they are numerically equivalent. To ensure this is clear, the calculator will output the following by way of example : "1 Gy/h = 1 Sv/h (assumes wR=1, wT=1)". Use this type of conversion cautiously. For further information the following Ionactive link may be useful: Radiation Exposure - Dose and Dose Rate (the Gray & Sievert).

Shielding. In this category you will find TVT (10th value thickness), HVT (1/2 value thickness) and attenuation.  It is important to note that these are not radiation energy or material specific - you will need to look up appropriate values for your particular situation. What this calculator does is convert between numbers of TVT and HVT, and between attenuation and TVT / HVT (and in reverse). For more information please read this Ionactive article: How reliable is TVT (10th Value Thickness) in radiation shielding calculations?

If you seek formal advice on radiation protection then please visit our commercial services page: Radiation Protection Adviser (RPA) Services.