Zerdly

Coordinate Offset Calculator

New coordinates from ΔE/ΔN, a bearing and distance, or along/across a baseline (positive across = right), with a reverse check and a CSV batch.

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How to use this calculator

Inputs

Move a point by ΔE/ΔN, by bearing and distance, or along/across a baseline (positive across = right) — singly or as a batch.

Applies to every coordinate, offset and tolerance on this form. Feet are converted exactly.

Start point
Offset
More options
Output

Independent of the unit. Labels and exports follow the order chosen.

Local transform (optional)

Mathematical CCW rotation about the origin below — NOT a survey bearing and NOT a datum conversion.

Enter the values and press Calculate.

Or load an example to see a worked result.

Along / across offset from a baseline
Not to scale — local origin
Along / across offset from a baselinePlan view with a north arrow, the start point, the offset components and the new point.Nalong aacross +c (right)StartNewLooking along the baseline: + across = right, − = left
Plan: from the start point, the along component runs with the baseline and the across component is perpendicular — positive to the right, negative to the left.
Calculate first: a stale result cannot be exported.

Batch from CSV

One row per calculation, with a header row. Values use the units currently selected in the form above. Up to 10,000 rows; nothing is uploaded.

Before you rely on this: First-pass guide only. Verify safety-critical or regulated work against the relevant standards, your project requirements and a qualified professional.

How to use this calculator

  1. Choose how the offset is given: ΔE/ΔN, bearing and distance, along/across a baseline, or a CSV batch.
  2. Enter the start point (RL optional) and the offset. Bearings accept decimal degrees or DMS.
  3. For along/across, positive across is to the RIGHT looking along the baseline; a negative value goes left.
  4. Press Calculate. The reverse check shows the difference back to the start.

How it works

E′ = E + ΔE, N′ = N + ΔN, and H′ = H + ΔH only when a start RL exists — a ΔRL alone cannot invent one.

Bearing and distance: ΔE = d·sin θ, ΔN = d·cos θ with θ clockwise from grid north. Along a and across c on a baseline of bearing θ: ΔE = a·sin θ + c·cos θ, ΔN = a·cos θ − c·sin θ. A baseline from two coincident points has no direction and is refused.

An optional local rigid transform rotates ANTICLOCKWISE about an origin you choose and then translates — labelled apart from survey bearings and never called a datum conversion. Output order E, N, H or N, E, H is independent of the unit.

Worked example

Along 10 m, across 5 m right of a north baseline from E1000 N2000. θ = 0°, so ΔE = 10·0 + 5·1 = 5 and ΔN = 10·1 − 5·0 = 10: the new point is E1005 N2010 (right of a northward line is east). On an eastward baseline (θ = 90°) the same offset gives E1010 N1995, the same as a plain +10 E, −5 N.

Frequently asked questions

Which side is positive across?

Right, looking along the baseline from its start. Enter a negative across value for the left; the sign you type is kept and labelled.

Is the result a ground position?

It is a grid movement on the coordinates' own reference. No scale factor or datum change is applied.

How does the batch keep per-row offsets safe?

Choose per-row ΔE/ΔN columns or one common offset. A common offset is refused if the file also has delta columns, and failed rows are reported, never dropped.

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Cite this tool

Zerdly. (2026). Coordinate Offset Calculator. Retrieved from https://www.zerdly.com/tools/coordinate-offset-calculator/

Tip: Enter any known values to calculate the remaining results.

Designed to run locally in your browser. Tool inputs are not intentionally stored by Zerdly unless stated otherwise.