# Money calculators API

> SIP, EMI, GST, income tax, HRA, gratuity, PPF, capital gains and trade charges.

Indian money sums with the rules written in: each answer names the rule and the year it used. Income tax knows the financial years 2026-27 and 2025-26, both regimes. For planning: not tax or financial advice. Amounts are in rupees; commas are allowed.

Base URL `https://api.dharun.dev`. No API key needed for most endpoints; a free key (https://api.dharun.dev/keys) raises the limits, and the model endpoints marked below will need one. Answers are JSON, `{ "data": ..., "meta": { ... } }`, and errors are `{ "error": { "code", "message" } }` with a matching HTTP status. Rate limit: 600 units a minute per address without a key, 3000 per key; the `RateLimit-*` headers say what is left.

## SIP returns

`GET /v1/calc/sip`

What a monthly investment grows to, year by year, with an optional yearly step-up of the amount.

Parameters:

- `monthly` (query, required): Monthly amount.
- `rate` (query, required): Expected return, percent a year.
- `years` (query, required): 1 to 60.
- `stepup` (query): Yearly increase of the monthly amount, percent.

Example: https://api.dharun.dev/v1/calc/sip?monthly=10000&rate=12&years=10&utm_medium=docs-md

Response, with lists and long text shortened:

```json
{
  "data": {
    "invested": 1200000,
    "value": 2323390.76,
    "gain": 1123390.76,
    "years": [
      {
        "year": 1,
        "monthly": 10000,
        "invested": 120000,
        "value": 128093.28
      },
      {
        "year": 2,
        "monthly": 10000,
        "invested": 240000,
        "value": 272432
      },
      {
        "year": 3,
        "monthly": 10000,
        "invested": 360000,
        "value": 435076.47
      }
    ],
    "rule": "Each instalment is invested at the start of the month and grows at the yearly return divided by 12, compounded monthly.",
    "inputs": {
      "monthly": 10000,
      "returnPercent": 12,
      "years": 10,
      "stepUpPercent": 0
    }
  },
  "meta": {
    "note": "A calculation from the rules named in rule, for planning. It is not tax or financial advice; check figures that matter with the source or an adviser."
  }
}
```

## Lump sum growth

`GET /v1/calc/lumpsum`

Parameters:

- `amount` (query, required): Amount invested once.
- `rate` (query, required): Expected return, percent a year.
- `years` (query, required): 1 to 60.

Example: https://api.dharun.dev/v1/calc/lumpsum?amount=100000&rate=10&years=10&utm_medium=docs-md

Response:

```json
{
  "data": {
    "invested": 100000,
    "value": 259374.25,
    "gain": 159374.25,
    "rule": "Compounded once a year."
  },
  "meta": {
    "note": "A calculation from the rules named in rule, for planning. It is not tax or financial advice; check figures that matter with the source or an adviser."
  }
}
```

## Loan EMI and schedule

`GET /v1/calc/emi`

The monthly instalment of a reducing-balance loan, the total interest and, with schedule=true, every month's split of interest and principal.

Parameters:

- `amount` (query, required): Loan amount.
- `rate` (query, required): Interest, percent a year.
- `years` (query): Term in years (or give months).
- `months` (query): Term in months, 1 to 600.
- `schedule` (query): true adds the month-by-month schedule.

Example: https://api.dharun.dev/v1/calc/emi?amount=1000000&rate=8.5&years=20&utm_medium=docs-md

Response:

```json
{
  "data": {
    "emi": 8678.23,
    "totalInterest": 1082775.76,
    "totalPaid": 2082775.76,
    "rule": "Reducing balance, interest charged monthly at the yearly rate divided by 12."
  },
  "meta": {
    "note": "A calculation from the rules named in rule, for planning. It is not tax or financial advice; check figures that matter with the source or an adviser."
  }
}
```

## GST split

`GET /v1/calc/gst`

Adds GST to an amount, or takes it out of one that includes it, split into CGST and SGST within a state or IGST between states.

Parameters:

- `amount` (query, required): The amount.
- `rate` (query, required): GST rate: 0, 0.1, 0.25, 1.5, 3, 5, 12, 18, 28 or 40.
- `inclusive` (query): true when the amount already includes GST.
- `interstate` (query): true for a supply between states (IGST).

Example: https://api.dharun.dev/v1/calc/gst?amount=1180&rate=18&inclusive=true&utm_medium=docs-md

Response:

```json
{
  "data": {
    "taxable": 1000,
    "rate": 18,
    "tax": 180,
    "cgst": 90,
    "sgst": 90,
    "total": 1180,
    "interstate": false,
    "rule": "Within a state the tax is charged as CGST and SGST, half each; between states, or on imports, as IGST."
  },
  "meta": {
    "note": "A calculation from the rules named in rule, for planning. It is not tax or financial advice; check figures that matter with the source or an adviser."
  }
}
```

## Income tax, old and new regime

`GET /v1/calc/income-tax`

Tax on a year's income under the new regime (section 115BAC) and the old one, with the section 87A rebate, surcharge, marginal relief and 4% cess, slab by slab, and which regime costs less. Special-rate income such as capital gains is not included.

Parameters:

- `income` (query, required): Gross total income for the year, before the standard deduction.
- `year` (query): Financial year. Default the newest. One of: 2026-27, 2025-26.
- `regime` (query): Default both. One of: both, new, old.
- `age` (query): Changes the old regime's exemption limit. Default below60. One of: below60, 60to80, 80plus.
- `salaried` (query): Salary or pension, so the standard deduction applies. Default true.
- `deductions` (query): Old regime deductions and exemptions in all (80C, 80D, HRA, home loan interest...).

Example: https://api.dharun.dev/v1/calc/income-tax?income=1500000&year=2025-26&utm_medium=docs-md

Response, with lists and long text shortened:

```json
{
  "data": {
    "year": "2025-26",
    "new": {
      "regime": "new",
      "taxableIncome": 1425000,
      "standardDeduction": 75000,
      "deductions": 0,
      "slabs": [
        {
          "from": 0,
          "to": 400000,
          "rate": 0,
          "amount": 400000,
          "tax": 0
        },
        {
          "from": 400000,
          "to": 800000,
          "rate": 5,
          "amount": 400000,
          "tax": 20000
        },
        {
          "from": 800000,
          "to": 1200000,
          "rate": 10,
          "amount": 400000,
          "tax": 40000
        }
      ],
      "taxOnIncome": 93750,
      "rebate87A": 0,
      "surcharge": 0,
      "cess": 3750,
      "total": 97500,
      "perMonth": 8125,
      "effectiveRatePercent": 6.5,
      "marginalRelief": false
    },
    "old": {
      "regime": "old",
      "taxableIncome": 1450000,
      "standardDeduction": 50000,
      "deductions": 0,
      "slabs": [
        {
          "from": 0,
          "to": 250000,
          "rate": 0,
          "amount": 250000,
          "tax": 0
        },
        {
          "from": 250000,
          "to": 500000,
          "rate": 5,
          "amount": 250000,
          "tax": 12500
        },
        {
          "from": 500000,
          "to": 1000000,
          "rate": 20,
          "amount": 500000,
          "tax": 100000
        }
      ],
      "taxOnIncome": 247500,
      "rebate87A": 0,
      "surcharge": 0,
      "cess": 9900,
      "total": 257400,
      "perMonth": 21450,
      "effectiveRatePercent": 17.16,
      "marginalRelief": false
    },
    "better": "new",
    "saves": 159900,
    "rule": "Section 115BAC (new regime) and the slabs of the Finance Act (old regime) for the financial year 2025-26; rebate under section 87A with marginal relief; surchar…",
    "inputs": {
      "income": 1500000,
      "year": "2025-26",
      "age": "below60",
      "salaried": true,
      "deductions": 0
    }
  },
  "meta": {
    "note": "A calculation from the rules named in rule, for planning. It is not tax or financial advice; check figures that matter with the source or an adviser."
  }
}
```

## HRA exemption

`GET /v1/calc/hra`

The tax-free part of house rent allowance under section 10(13A). Give every amount for the same period (a month or a year).

Parameters:

- `basic` (query, required): Basic pay plus dearness allowance.
- `hra` (query, required): HRA received.
- `rent` (query, required): Rent paid.
- `metro` (query): true in Delhi, Mumbai, Kolkata or Chennai.

Example: https://api.dharun.dev/v1/calc/hra?basic=50000&hra=25000&rent=20000&metro=true&utm_medium=docs-md

Response, with lists and long text shortened:

```json
{
  "data": {
    "exempt": 15000,
    "taxable": 10000,
    "limits": [
      25000,
      15000,
      25000
    ],
    "rule": "Section 10(13A) and rule 2A: the least of the HRA received, rent paid less 10% of salary, and 50% of salary in Delhi, Mumbai, Kolkata or Chennai (40% elsewhere)…"
  },
  "meta": {
    "note": "A calculation from the rules named in rule, for planning. It is not tax or financial advice; check figures that matter with the source or an adviser."
  }
}
```

## Gratuity

`GET /v1/calc/gratuity`

Parameters:

- `salary` (query, required): Last monthly basic pay plus dearness allowance.
- `years` (query, required): Years of service; 10.6 is ten years and about seven months.
- `covered` (query): Covered by the Payment of Gratuity Act. Default true.

Example: https://api.dharun.dev/v1/calc/gratuity?salary=52000&years=10.6&utm_medium=docs-md

Response, with lists and long text shortened:

```json
{
  "data": {
    "amount": 330000,
    "yearsCounted": 11,
    "taxFree": 330000,
    "taxable": 0,
    "eligible": true,
    "rule": "Payment of Gratuity Act, section 4: 15 days' wages (basic pay and dearness allowance, the month taken as 26 days) for each completed year of service; more than …"
  },
  "meta": {
    "note": "A calculation from the rules named in rule, for planning. It is not tax or financial advice; check figures that matter with the source or an adviser."
  }
}
```

## PPF maturity

`GET /v1/calc/ppf`

Parameters:

- `yearly` (query, required): Yearly deposit, 500 to 1,50,000.
- `years` (query): 15, or 15 plus blocks of 5. Default 15.
- `rate` (query): Interest, percent a year. Default the current rate.

Example: https://api.dharun.dev/v1/calc/ppf?yearly=150000&years=15&utm_medium=docs-md

Response, with lists and long text shortened:

```json
{
  "data": {
    "deposited": 2250000,
    "interest": 1818209,
    "maturity": 4068209,
    "years": [
      {
        "year": 1,
        "interest": 10650,
        "balance": 160650
      },
      {
        "year": 2,
        "interest": 22056,
        "balance": 332706
      },
      {
        "year": 3,
        "interest": 34272,
        "balance": 516978
      }
    ],
    "rule": "Deposits made by 5 April each year earn interest for the whole year, compounded yearly at 7.1%. The rate is set every quarter; 7.1% is the current one."
  },
  "meta": {
    "note": "A calculation from the rules named in rule, for planning. It is not tax or financial advice; check figures that matter with the source or an adviser."
  }
}
```

## Capital gains tax

`GET /v1/calc/capital-gains`

Short or long term, and the tax at the rates for sales from 23 July 2024: shares and equity funds, debt funds, property (with the indexation choice for land and buildings bought before that date), gold and other assets.

Parameters:

- `asset` (query, required): What was sold. One of: equity, equity-fund, debt-fund, property, gold, other.
- `bought` (query, required): Purchase date, YYYY-MM-DD.
- `sold` (query, required): Sale date, from 2024-07-23.
- `cost` (query, required): Purchase cost with improvement costs.
- `price` (query, required): Sale price.
- `expenses` (query): Costs of the sale.

Example: https://api.dharun.dev/v1/calc/capital-gains?asset=equity&bought=2023-01-10&sold=2025-01-10&cost=100000&price=400000&utm_medium=docs-md

Response, with lists and long text shortened:

```json
{
  "data": {
    "term": "long",
    "gain": 300000,
    "ratePercent": 12.5,
    "exemption": 125000,
    "tax": 21875,
    "cess": 875,
    "total": 22750,
    "rule": "Section 112A: listed shares and equity funds held over 12 months, with securities transaction tax paid. 12.5% on gains above 1.25 lakh a year (the exemption is …"
  },
  "meta": {
    "note": "A calculation from the rules named in rule, for planning. It is not tax or financial advice; check figures that matter with the source or an adviser."
  }
}
```

## Share trade charges

`GET /v1/calc/trade`

Every charge on buying and selling an NSE share (STT, exchange charges, SEBI fee, stamp duty, GST), the net profit and the move needed to break even.

Parameters:

- `buy` (query, required): Buy price per share.
- `sell` (query, required): Sell price per share.
- `quantity` (query, required): Shares.
- `kind` (query): Default delivery. One of: delivery, intraday.
- `brokerage` (query): Your broker's charge per order, in rupees.
- `dp` (query): Depository charge on a delivery sale.

Example: https://api.dharun.dev/v1/calc/trade?buy=1000&sell=1100&quantity=100&kind=delivery&brokerage=20&utm_medium=docs-md

Response, with lists and long text shortened:

```json
{
  "data": {
    "turnover": 210000,
    "charges": {
      "brokerage": 40,
      "dp": 0,
      "exchange": 6.24,
      "gst": 8.36,
      "sebi": 0.21,
      "stampDuty": 15,
      "stt": 210
    },
    "totalCharges": 279.81,
    "grossProfit": 10000,
    "netProfit": 9720.19,
    "breakevenPoints": 2.8,
    "rule": "NSE equity charges from 1 October 2024: STT, NSE transaction charges 0.00297%, SEBI fee 10 rupees a crore, stamp duty on the buy, and 18% GST on brokerage and t…"
  },
  "meta": {
    "note": "A calculation from the rules named in rule, for planning. It is not tax or financial advice; check figures that matter with the source or an adviser."
  }
}
```