In Dragon's Den, an entrepreneur asking for £100,000 for 20% is offering 20% of the business.
The percentage represents the equity stake offered to an investor in exchange for capital. If the requested investment were accepted exactly as proposed, the entrepreneur would retain the remaining 80%, while the investor would own one-fifth of the company. The implied valuation would be £500,000, because £100,000 represents 20% of that total.
Actual negotiations frequently change both the money and the equity. A dragon may offer a different sum, request a larger share, or propose a loan or another structure. Therefore, the percentage stated in a pitch is the opening offer, not necessarily the final deal.
The programme is about investment for ownership, not a simple prize or donation. That distinction explains why equity percentages are central to its negotiations.