As written, do NOT take this offer. At such a low salary, you're a founder, not an employee, and deserve to be treated like one. When you take a deal like thi

As written, do NOT take this offer. At such a low salary, you're a founder, not an employee, and deserve to be treated like one. When you take a deal like this (low salary, low equity, because the founders have a track record of raising money) you are paying for connections. How connected are they? So far, they've only done something you could do (join an accelerator, and crowd-fund). I don't think you should sell your labor at a discount for their "connections". (I'm going to convert these numbers into dollars, just because it's easier to use one currency.) You're making $2,375 per month, or $28,500 per year. That won't even cover rent in a major city. Let's do the math. I'm going to compute a fair equity slice for you. An intermediate-to-senior level developer (7 years experience) is worth at least $100,000 per year. (Bay Area: $150k, New York, Seattle: $135k, Austin: $125k, Midwest: $110k.) That's about £58,000. Now, I get that startups often pay less, but you need to know what you're worth in order to figure out how much equity you should get. If you're worth $100k (and you're worth at least that, if you're intermediate-to-senior level) and making $28.5k, you're putting $71.5k per year into the business. Let me add a few things to consider. First, you're not getting the typical big-company benefits (in the US: 401k matching, conference attendance, health insurance) which are probably worth $15k a year in addition. Second, raises are rare in startups. When things are going well, the equity appreciation is the raise (even if that enrichment is illiquid) and when things are going badly, it's not a time to ask for things. So, if you stay for 4 years, you're forgoing four years of raises. That's another $60k or so ($10k in year 2, $20k in year 3, $30k in year 4). Third, there's more risk in a startup. People are fired more quickly, and while traditional corporations tend to call it a layoff and pay severance unless you do something illegal, startups fire people without severance all the time. I'd price that risk at $10k per year. All-in, the total opportunity cost is $446,000 over four years. That is, in effect, what you'd be paying (one could argue for lending, but at zero interest) to work there. Now, what is the business worth? It might be worth $4 million to VCs, who get some measure of control of the company. Unlike you, VCs are nearly impossible to fire. They also have a lot of capital to invest; their job is to do exactly that. The company is worth less to you. Also, all you have to justify the $4 million claim (which is where the company will be valued if it is funded) is the founders' statement. I'm going to put the startup's value (including the work you'll put into it) at $2.5 million. That's generous. If the founders aren't connected, it's less than that. With those numbers, you're putting $446k into a startup around $2.5 million, and argue for 17.8 percent. Even that, I think, is low.