$25/h..
I'm in Europe though.. but when I look at your numbers I want to cry.
That's very a lot to my taste.
Edit: did calculations.. even $24/h ($46800/year)
It depends where in Europe you live, and what are your other costs.
I'm Spanish, and in Spain I can go to the doctor and (for now) not have to pay at the front desk. In Australia, my local doctor charges an $30 Australian (20 Euro) co-pay per visit.
Coffee and churros in Madrid is 1.70 Euro ($2.50 Australian). Coffee alone in our neighbourhood in Australia is never under $3 Au (2 euro). Thanks to the Coles/Woolworths duopoly, I reckon Aussie supermarket prices in general are from 1.5 to 3 times more expensive in Australia than in Spain. Only beef is consistently cheaper in Australia, and milk is the same price, being a loss leader.
And the real estate bubble continues in Australia, so house prices and rents keep going up. This is why I asked Aussie devs to share their rates: they are working in the same market, but also they are paying for food, housing, healthcare etc. in the same market.
Also, remember that if you are a full time employee you are accruing other benefits, and your pay is calculated taking into account you lower risk of unemployment and higher severance in case of dismissal (especially in the many European countries with very strict labor laws favouring employees, like Spain). I reckon $50-$60/h is the freelance-equivalent rate of $46800/year full time salary in Europe.
And if you work on 3 startups, you may be giving up some salary in exchange for equity. If you don't get equity, well, your problem is not your salary.