香蕉等效剂量（Banana Equivalent Dose，简称BED）是一种非正式的游离辐射（ionizing radiation）剂量单位，旨在向大众表明吃下一个中等大小香蕉可能受到天然放射性同位素辐射的剂量。

香蕉等效剂量在1995年于RadSafe通信数据提出。

1香蕉等效剂量=0.0778微西弗。计算的依据主要是由于香蕉含有大量的钾元素，天然钾当中约有117/10000 (0.0117%)的放射性钾，钾40。钾40由于半衰期长达12亿5千万年(地球寿命为45亿年)，因此每1公克天然钾中，约含有31贝克勒(放射性活度单位)的钾40。而1根香蕉中，平均而言约含有0.5公克的天然钾，所以每根香蕉约含有15.5贝克勒的放射性钾(钾40)。在依据美国环境保护署 (US Environment Protection Agency，EPA)提供的转换因数，每贝克的钾40，平均对每个成年人造成的等效剂量0.00502微西弗，所以，1根香蕉的等效剂量=(15.5贝克勒)(0.00502微西弗/贝克勒)=0.0778微西弗

A banana equivalent dose (BED) is an informal expression of ionizing radiation exposure, intended as a general educational example to indicate the potential dose due to naturally occurring radioactive isotopes by eating one average-sized banana. One BED is often taken as 0.1 µSv, however, in practice this dose is not cumulative, as the principal radioactive component is excreted to maintain metabolic equilibrium. The BED is only an indicative concept meant to show the existence of very low levels of natural radioactivity within a natural food and is not a formally adopted dose quantity.