---
title: "GET /public/get_contract_size"
method: GET
path: "/public/get_contract_size"
tags: ["Market Data", "Public"]
---

# GET /public/get_contract_size

`GET /public/get_contract_size`

Retrieves the contract size (also known as contract multiplier) for a given instrument. The contract size is the value of one contract, expressed in the same unit as the order amount: USD for inverse (reversed) futures and perpetuals, and the base currency coin for options, spots, and linear futures and perpetuals.

This value is essential for calculating position values, margin requirements, and P&L calculations. Different instruments may have different contract sizes.

[Try in API console](https://test.deribit.com/api_console?method=%2Fpublic%2Fget_contract_size)

## Query parameters

- `instrument_name` string, required — Unique instrument identifier

## Response `200`

Success response

- PublicGetContractSizeResponse
  - `jsonrpc` '2.0', required — The JSON-RPC version (2.0)
  - `id` integer — The id that was sent in the request
  - `result` object, required
    - `contract_size` number, required — Contract size for the instrument, expressed in the same unit as the order amount. For inverse (reversed) futures and perpetuals this is USD — BTC-PERPETUAL has a contract size of 10 USD. For options, spots, and for linear futures and perpetuals it is the base currency coin — BTC_USDC-PERPETUAL has a contract size of 0.0001 BTC. Note that on an inverse instrument `base_currency` identifies the underlying and settlement coin and does not indicate the unit of `contract_size`.

---

[API](https://skmtc.net/deribit/apis/deribit-api-2.md) · [All operations](https://skmtc.net/deribit/apis/deribit-api-2/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/deribit/deribit-api-2/revisions/8dfbbe9fdddf/schema)