Single Premium (Lump Sum) Calculator Use this to estimate the future value of a lump sum investment. Investment (£): * Annual Growth/Interest (%): * Enter 6% as 6. Calculator Notes: This calculator assumes that charges are as per L&G 100 Index Fund. Your actual charges may be higher or lower. The calculator assumes that the 4, 6, 8 per cent growth rates rules apply. The value of investments can fall as well as rise and you may not get back the amount you originally invested. Past performance is not a guide to future performance.