Half of $15 is $7.50, so time and a half lands at $22.50 per hour. That's the floor for FLSA overtime at this wage — some states' daily rules and many contracts use the same 1.5x rate for other premium hours too.
A 40-hour week at $15/hour grosses $600; add 10 overtime hours and it's $825. Because overtime hours pay 1.5x, those 10 hours deliver the earnings of 15 regular ones — the fastest honest raise available without renegotiating your wage (about $31,200/year at full time).
Working these hours in 2025–2028? The $7.50/hour premium portion may be federally deductible — see the no tax on overtime calculator. And if your employer pays 2x for some hours, that's $30.00/hour — the double time calculator covers it.