Practice · Calculators
Real-life calculators
Seven small calculators for the sums people ask a chatbot about every day. Do them here and you can check what the AI tells you.
Kit
AI is good at explaining a loan and surprisingly bad at adding it up. I do the arithmetic here in plain code, so you can check any answer it gives you.
Pick a calculator
True cost of a loan
Two offers can quote the same rate and cost very different amounts. A flat rate (lãi phẳng) charges interest on the whole loan every month, even after you've paid most of it back. A reducing-balance rate charges interest only on what you still owe.
Your numbers
Processing fee, bundled insurance. Leave 0 if none.
What it comes to
Your offer: 18% · Flat rate
True yearly rate
31.5%
The reducing-balance rate that costs the same, fees included. Use it to compare offers.
Total you pay back
₫40,800,000
Total interest: ₫10,800,000
First month
₫1,700,000
Last month
₫1,700,000
Same rate, both ways · Total interest
That 18% flat rate really works like about 31.5% on a reducing balance. Ask the lender for the reducing-balance rate and the total you'll repay, in writing.
- Ask: is this rate flat or on the reducing balance? Is it per month or per year?
- Ask for the total amount you will repay and every fee, in writing, before you sign.
- Insurance added to a loan is often optional. You can ask to remove it.
Month-by-month schedule
| Month | Interest | Payment | Still owed |
|---|---|---|---|
| 1 | 450,000 | 1,700,000 | 28,750,000 |
| 2 | 450,000 | 1,700,000 | 27,500,000 |
| 3 | 450,000 | 1,700,000 | 26,250,000 |
| 4 | 450,000 | 1,700,000 | 25,000,000 |
| 5 | 450,000 | 1,700,000 | 23,750,000 |
| 6 | 450,000 | 1,700,000 | 22,500,000 |
| 7 | 450,000 | 1,700,000 | 21,250,000 |
| 8 | 450,000 | 1,700,000 | 20,000,000 |
| 9 | 450,000 | 1,700,000 | 18,750,000 |
| 10 | 450,000 | 1,700,000 | 17,500,000 |
| 11 | 450,000 | 1,700,000 | 16,250,000 |
| 12 | 450,000 | 1,700,000 | 15,000,000 |
| 13 | 450,000 | 1,700,000 | 13,750,000 |
| 14 | 450,000 | 1,700,000 | 12,500,000 |
| 15 | 450,000 | 1,700,000 | 11,250,000 |
| 16 | 450,000 | 1,700,000 | 10,000,000 |
| 17 | 450,000 | 1,700,000 | 8,750,000 |
| 18 | 450,000 | 1,700,000 | 7,500,000 |
| 19 | 450,000 | 1,700,000 | 6,250,000 |
| 20 | 450,000 | 1,700,000 | 5,000,000 |
| 21 | 450,000 | 1,700,000 | 3,750,000 |
| 22 | 450,000 | 1,700,000 | 2,500,000 |
| 23 | 450,000 | 1,700,000 | 1,250,000 |
| 24 | 450,000 | 1,700,000 | 0 |
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