Pagination offset and limit calculator

Provide the requested page, the number of records allowed on each page, and the total number of available items. The calculator returns the zero-based offset, the query limit, and the total page count. It also rejects page numbers or page sizes below one, helping prevent invalid database requests and inconsistent navigation controls before they reach application code.

Convert a page request into query parameters

User interfaces usually describe pagination with human-friendly page numbers, while databases and APIs often expect a zero-based offset plus a limit. This calculator connects those two conventions. Enter a page number beginning at one, a page size, and the total number of items in the full collection. The offset is calculated as the page number minus one, multiplied by the page size. The limit is the page size itself. For example, the third page of a collection displayed twenty-five items at a time starts after the first fifty items, so its offset is fifty and its limit is twenty-five. These values can be passed directly to a typical SQL LIMIT and OFFSET clause or mapped to equivalent request parameters in another service. The result is deterministic and does not inspect or fetch the underlying records. It only performs the arithmetic needed to prepare a paginated request, making it useful in backends, scripts, tests, documentation, and debugging sessions.

Understand total pages and boundary behavior

The total page count is the total item count divided by the page size and rounded upward. Rounding upward matters because a partially filled final page is still a page. If one hundred and one items are displayed twenty-five at a time, four pages hold one hundred items and a fifth page holds the remaining item. When the total item count is zero, the total page count is zero because there is no result page to display. The requested page is not clamped to that total. A request for page ten can therefore produce a valid offset even when the collection contains only three pages. That behavior is intentional: the calculator reports pagination arithmetic and leaves application policy to the caller. Your application can compare the requested page with total_pages and then return an empty result, redirect to the last page, or show a not-found response. Keeping calculation separate from policy makes the output predictable across database, REST, and user-interface workflows.

Validate inputs before building a query

Page and page_size must be safe integers greater than or equal to one. A zero or negative value would break the one-based page convention or create a meaningless limit, so either condition produces an invalid-input error. total_items must be a safe integer greater than or equal to zero because a collection cannot contain a negative or fractional number of records. Safe-integer checks also prevent silent precision loss in JavaScript when very large values are multiplied. If the computed offset exceeds the safe integer range, the request is rejected instead of returning an inaccurate number. These rules are useful beyond this calculator: applying the same validation at an API boundary prevents malformed query parameters from reaching a database adapter. The capability performs no network requests, stores no data, and uses no random or time-dependent values. The same input always produces the same output. For API automation, each request costs $0.002; the browser experience can be used to check examples while designing or troubleshooting pagination logic.