Savings Goal Calculator & Tracker

# Savings Goal Calculator & Tracker

Calculate how long it takes to reach any savings goal with compound interest, generate a monthly savings plan, and track progress.

## When to Use

- "How long to save $10,000 for a trip?"
- "Create a savings plan for a house down payment"
- "Track my emergency fund progress"

## Requirements

- **python3** for compound interest calculations

## Workflow

### Step 1 — Collect Goal Details

- **Goal name** (emergency fund, vacation, down payment, etc.)
- **Target amount**
- **Current savings** (starting balance)
- **Monthly contribution** (how much can you save per month?)
- **Interest rate** (savings account APY, default 4.5%)
- **Deadline** (optional — if set, calculate required monthly contribution)

### Step 2 — Calculate Timeline

```bash
python3 << 'PYEOF'
import math

goal = {TARGET_AMOUNT}
current = {CURRENT_SAVINGS}
monthly = {MONTHLY_CONTRIBUTION}
apy = {INTEREST_RATE} / 100  # e.g., 4.5 -> 0.045
monthly_rate = apy / 12

if monthly <= 0:
    print("ERROR: Monthly contribution must be positive")
else:
    balance = current
    months = 0
    schedule = []
    
    while balance < goal and months < 600:  # cap at 50 years
        interest = balance * monthly_rate
        balance += monthly + interest
        months += 1
        schedule.append({
            "month": months,
            "contribution": monthly,
            "interest": round(interest, 2),
            "balance": round(balance, 2)
        })
    
    years = months // 12
    remaining_months = months % 12
    total_contributed = current + (monthly * months)
    total_interest = balance - total_contributed
    
    print(f"Goal: ${goal:,.2f}")
    print(f"Timeline: {years}y {remaining_months}m ({months} months)")
    print(f"Total contributed: ${total_contributed:,.2f}")
    print(f"Interest earned: ${total_interest:,.2f}")
    print(f"Final balance: ${balance:,.2f}")
    
    # Print milestone markers
    milestones = [25, 50, 75, 100]
    for pct in milestones:
        target_bal = goal * pct / 100
        for s in schedule:
            if s['balance'] >= target_bal:
                print(f"  {pct}% (${target_bal:,.0f}) reached at month {s['month']}")
                break
PYEOF
```

### Step 3 — Generate Savings Plan

```markdown
# Savings Goal: {NAME}

| | |
|---|---|
| 🎯 Target | ${GOAL} |
| 💰 Current | ${CURRENT} |
| 📅 Monthly savings | ${MONTHLY} |
| 📈 APY | {RATE}% |
| ⏱️ Time to goal | {Y}y {M}m |
| 💵 Interest earned | ${INTEREST} |

## Milestones
| Milestone | Amount | Month | Date |
|-----------|--------|-------|------|
| 25% | ${X} | Month {N} | {DATE} |
| 50% | ${X} | Month {N} | {DATE} |
| 75% | ${X} | Month {N} | {DATE} |
| 100% 🎉 | ${X} | Month {N} | {DATE} |

## Progress Tracker
- [ ] Month 1: Save ${MONTHLY} → Balance: ${X}
- [ ] Month 2: Save ${MONTHLY} → Balance: ${X}
- [ ] Month 3: Save ${MONTHLY} → Balance: ${X}
...
```

### Step 4 — Save Plan

```bash
mkdir -p outputs/finance
cat > "outputs/finance/savings-goal-{NAME}.md" << 'EOF'
{SAVINGS_PLAN}
EOF
```

## Important Rules

- Use realistic savings account rates (current HYSA rates ~4-5% APY)
- Never provide investment advice or recommend specific accounts
- If timeline is unrealistically long, suggest increasing monthly contribution
- Account for inflation on long-term goals (5+ years)

## Example Prompts

- "How long to save $10,000 if I save $500/month?"
- "Create a savings plan for a $60,000 down payment"
- "I have $2,000 saved, need $15,000 by December — how much per month?"