“投资额”的英语可以翻译为：amount of investment，amount invested ...

我方出资大约占总投资额的51%.We lay out about 51 % of the total investment.他的投资额达五百万元.His investments amount to five million dollars.企业创造出的资金远远超过了它们的投资额.Businesses are wildly generating more money than they're using to invest....