There are several methods that a startup can use to calculate its valuation, including:

1. Comparable companies method: This involves comparing the startup to similar companies in the same industry, and using the valuations of those companies as a benchmark.
2. Earnings multiples method: This involves using the company’s expected earnings or revenue as a basis for valuation, and applying a multiple based on industry benchmarks or the company’s growth potential.
3. Discounted cash flow method: This involves projecting the company’s future cash flows and using a discount rate to calculate the present value of those cash flows.
4. Market capitalization method: This involves calculating the company’s valuation based on the total value of its outstanding shares, using the market price of those shares.
5. Net asset value method: This involves calculating the company’s valuation based on the value of its assets, such as property, equipment, and intellectual property, minus any liabilities.

Each of these methods has its own pros and cons, and the most appropriate method will depend on the specific circumstances of the startup. It is important to carefully consider the strengths and weaknesses of each method, and to seek the advice of financial and legal professionals if necessary.