From Wikipedia, the free encyclopedia. Phototoxicity, also called photoirritation, is a chemically induced skin irritation, requiring light, that does not involve the immune system. It is a type of photosensitivity. The skin response resembles an exaggerated sunburn.
Contribution margin ratio measures the percentage of sales that would increase net income. To calculate it, divide contribution margin by sales, either in total or per unit: Suppose a gadget selling for $100 per unit brings in $40 per unit of contribution margin.
Gross Profit Margin Ratio. Definition. Gross Profit Margin Ratio is the percentage of gross profit relative to the revenue earned during a period. Gross Profit Margin Ratio is also known as Gross Margin Percentage and GP Margin Ratio. Formula