Emergency Fund Calculator

def emergency_fund_target(monthly_expenses, months=6):
    """Calculate the target emergency fund amount."""
    return round(monthly_expenses * months, 2)

def months_to_goal(target, current_savings, monthly_contribution):
    """How many months to reach the emergency fund goal."""
    if monthly_contribution <= 0:
        return float("inf")
    remaining = target - current_savings
    if remaining <= 0:
        return 0
    return -(-remaining // monthly_contribution)  # ceiling division

def progress_percent(current, target):
    """Percentage of goal reached."""
    return min(round((current / target) * 100, 1), 100)

# Example: $3,500/mo expenses, 6-month target
target = emergency_fund_target(3500, 6)   # 21000
print(f"Target: ${target:,.2f}")
print(f"Months to goal: {months_to_goal(target, 5000, 500)}")  # 32
print(f"Progress: {progress_percent(5000, target)}%")          # 23.8%