The offer is accompanied by an over-allotment facility of up to £10m, bringing the total fundraise to a potential £20m.
Calculus VCT offers investors a portfolio targeting sectors including technology, healthcare and entertainment, and currently holds Oxford BioTherapeutics, Optalix and Rotageek as part of the fund.
Calculus capitalises on lifted EIS sunset clause with new fund
The offer has a minimum investment threshold of £5,000, and the managers hope to attract "seasoned and new investors".
John Glencross, chief executive and co-founder of Calculus Capital, said: "Our journey since launching the first HMRC approved EIS fund in 1999, has been one of growth.
"With this VCT offer, we are further solidifying our pledge to back the UK's most promising businesses. We believe that through this VCT, investors can not only benefit from capital growth and tax-free dividends, but also play a pivotal role in shaping the future of the UK's innovation landscape."