The company – founded in 1991, and which now has outlets in Edinburgh, Dalkeith, Musselburgh and Dundee – said online income in the 12 months to April 2012 had hit £100,000, up from £35,000 in the previous period.
Paul Swadzba, founder and managing director, said the business had hired a computer programmer to build software to integrate its website and tills, and then invested further in revamping its online shop.
He said: "Our new website is modern and vibrant, with deep zoom images and full integration with our till system.
"This ensures stock levels are updated hourly. In addition, our links with larger sales platforms such as Amazon and eBay are increasing business daily, allowing us to diversify the offering and further increase sales."
Mr Swadzba said the growth in online sales had helped offset the access difficulties at its busiest store caused by the Edinburgh tram works.
He said: "We are determined to be positive, and have thrown everything we have at overcoming these obstacles."
He also confirmed the i-hire software was now being marketed to other kilt hire retailers, and added: "We hope in future to supply it to larger retailers and department stores that would like to try kilt hire."