ForHosting KIT · Unit converters

Surface charge density converter

1 C/m² is 0.0001 C/cm². Convert surface charge density between coulombs per square metre, centimetre, millimetre, inch and foot, plus milli-, micro- and nanocoulomb forms, for ESD labs, corona treatment and electrostatics homework. Free in your browser.

Free
Runs in your browser
No sign-up
Your data stays on your device

Run — free How it works & API

Use it from WebAPIEmailTelegramApp soon

Worked example

If you enter

Value: 1
Source unit: C/m2
Target unit: C/cm2

You get

Result: 0.0001
From label: coulomb per square metre
To label: coulomb per square centimetre
C per m2: 1

Surface charge density measures how much electric charge sits on a given area of a conductor, insulator film, or electrostatic sample. Engineers and students often receive values in coulombs per square metre from SI textbooks, coulombs per square centimetre from older lab notes, microcoulombs per square centimetre from corona and ESD literature, or coulombs per square inch from customary US datasheets—and need a trustworthy conversion without rebuilding factors by hand.

Supported units and exact conversion factors

The converter accepts nine surface charge density families under stable canonical codes: C/m2 for coulombs per square metre (SI), C/cm2 and C/mm2 for coulomb per square centimetre and millimetre, C/in2 and C/ft2 for coulomb per square inch and foot, plus mC/m2, uC/m2, nC/m2, and uC/cm2 for milli-, micro-, and nanocoulomb prefixes common in electrostatics.

Area factors follow SI definitions: one square centimetre is exactly ten to the minus four square metres, one square millimetre is ten to the minus six, one square inch is exactly zero point zero two five four metres squared, and one square foot is zero point three zero four eight metres squared.

Prefix units scale charge only: one millicoulomb per square metre is one thousandth of a coulomb per square metre, one microcoulomb per square metre is one millionth, one nanocoulomb per square metre is one billionth, and one microcoulomb per square centimetre equals one hundredth of a coulomb per square metre. Because the intermediate is always C/m², converting A to B and B to A is consistent up to the published twelve-decimal rounding, and there is no pairwise matrix that can drift out of sync.

Linear charge density, volume charge density, and raw electric charge are intentionally out of scope so electrostatic surface-charge users get predictable σ-only results under one clear convention.

Common surface charge tasks

Use the free in-browser surface charge density converter when you need a quick C/m² to C/cm², C/in² to C/m², or µC/cm² to C/m² check while reading a materials datasheet, electrostatics homework problem, corona-treatment specification, or ESD laboratory procedure. Open the page, enter the number and units, and copy the result without installing a spreadsheet, a unit library, or a desktop calculator pack. Source inputs follow the same retention rules as other KIT parse items, and results are safe to cache because the algorithm is fully deterministic.

Authors shipping mobile apps or chatbots can map the result and formula fields directly into cards that show both the number and the conversion path students, process engineers, and lab technicians expect on paper.

What you can do with it

ESD and corona-treatment labs

Convert µC/cm² and C/m² readings between corona treaters, charge plates, and SI reports so process windows stay comparable across instruments.

Textbook and homework electrostatics

Students convert C/m² problem statements into C/cm² or C/in² answers with exact SI inch and centimetre area factors and clear errors on typos.

FAQ

How is C/in² related to C/m²?

One square inch is exactly (0.0254 m)². The converter multiplies by 1/(0.0254)² so 1 C/in2 equals about 1550.0031 C/m2 with stable twelve-decimal rounding.

What if I send an unknown unit?

The message names the bad field and lists supported units; validation failures are not charged.

Is the surface charge density converter free?

The browser tool runs free on your device.

Does it convert volume or linear charge density?

No. This capability only converts surface charge density σ (charge per area). Linear λ and volume ρ charge densities are out of scope.

How many C/m² is 1 µC/cm²?

One microcoulomb per square centimetre is one hundredth of a coulomb per square metre. That unit is common in corona and ESD literature, so this conversion links those papers to SI textbooks.

Related tools

For developers — API access

Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.

API endpoint

POSThttps://api.kit.forhosting.com/conv/surface-charge-density

Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.

Call it from your stack

curl -X POST https://api.kit.forhosting.com/conv/surface-charge-density \
  -H "Authorization: Bearer $KIT_KEY" \
  -H "Content-Type: application/json" \
  -d '{"value":1,"from":"C/m2","to":"C/cm2"}'

const res = await fetch("https://api.kit.forhosting.com/conv/surface-charge-density", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.KIT_KEY}`,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    "value": 1,
    "from": "C/m2",
    "to": "C/cm2"
  })
});
const { task_id } = await res.json();

import os, requests

res = requests.post(
    "https://api.kit.forhosting.com/conv/surface-charge-density",
    headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
    json={
    "value": 1,
    "from": "C/m2",
    "to": "C/cm2"
},
)
task_id = res.json()["task_id"]

<?php
$res = file_get_contents("https://api.kit.forhosting.com/conv/surface-charge-density", false, stream_context_create([
  "http" => [
    "method"  => "POST",
    "header"  => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
    "content" => '{"value":1,"from":"C/m2","to":"C/cm2"}',
  ],
]));
$task = json_decode($res, true);

body := bytes.NewBufferString(`{"value":1,"from":"C/m2","to":"C/cm2"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/conv/surface-charge-density", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)

Example request

{
  "value": 1,
  "from": "C/m2",
  "to": "C/cm2"
}

Example response

{
  "task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
  "type": "conv.surface_charge_density",
  "status": "queued",
  "_links": {
    "result": "/tasks/tsk_…/result"
  }
}

The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.

Pricing

Per request$0.002

Published price — no tokens, no invented credits. A failed task is never charged.

Errors

HTTP	Code	Meaning
`401`	`unauthorized`	Missing or invalid API key.
`402`	`insufficient_balance`	Your balance doesn't cover the task price.
`404`	`unknown_type`	That task type doesn't exist.
`429`	`rate_limited`	Too many requests. Use the webhook instead of polling.

Technical notes

This capability converts a numeric surface charge density from one supported unit to another with fixed SI area definitions (inch exactly 0.0254 m, foot exactly 0.3048 m), routes every pair through C/m² as the intermediate base, and returns deterministic JSON for APIs, SDKs, and free browser use. Unknown unit names fail with a clear invalid_input error so forms and pipelines never silently invent a factor.

Supported units and exact conversion factors

Friendly aliases such as C/m², C/m^2, coulomb per square meter, microcoulomb/cm2, and µC/m² are normalized so forms can pass short codes or spelled names. Every request multiplies the input value by the exact coulombs-per-square-metre factor for the source unit, then divides by the factor for the target.

Request shape, response fields, and unknown-unit errors

The error message names the bad field and lists the supported set so clients can correct forms without guessing. Negative values are allowed when you need signed charge layers or polarity in electret and semiconductor work; zero converts cleanly to zero in every target unit. Send a JSON body with three required fields: value as a finite number, from as the source unit string, and to as the target unit string. Aliases amount, quantity, and sigma are accepted for value; unit_from and source for from; unit_to and target for to. On success the response echoes the canonical from and to codes, human-readable from_label and to_label strings, the converted result, the intermediate c_per_m2 quantity in coulombs per square metre, the dimensionless factor from source to target, a short formula line suitable for UI display, the method tag surface_charge_density_si, and the fixed list of units_supported. Missing value, non-finite numbers such as NaN or Infinity, missing unit fields, and any token that does not map to a supported unit fail with invalid_input and are not charged after the engine rejects the request. Identical inputs always yield identical JSON because the path is pure arithmetic with no randomness, no remote lookup, and no dependence on the wall clock, which makes the endpoint safe to pin in continuous-integration goldens and SDK contract tests. Microcoulomb-scale ESD results and coulomb-per-square-metre textbook results share the same code path, so extreme magnitude pairs remain well-defined as long as IEEE double precision can represent the intermediate product.

Browser use, API pricing, and everyday workflows

Switch to the prepaid API when a materials LIMS, plasma-process controller, semiconductor fab log, physics homework checker, or CAD electrostatic plugin must convert surface charge density at scale under a stable KIT contract at $0.002 per successful item; validation failures that raise invalid_input do not consume balance after rejection. Pair this endpoint with force or capacitance tools when a product pipeline needs several electromagnetic measure families, or call it alone when search traffic is specifically for surface charge density conversion—coulombs per square metre, centimetre, millimetre, inch, and foot, plus milli, micro, and nano prefixes—rather than a general unit switchboard.

Integration use cases

Materials and semiconductor pipelines

Automate surface charge density unit normalization in LIMS and fab logs via a prepaid, deterministic API instead of ad-hoc spreadsheet factors.

Technical questions

Which surface charge density units are supported?

C/m2, C/cm2, C/mm2, C/in2, C/ft2, mC/m2, uC/m2 (µC/m2), nC/m2, and uC/cm2 (µC/cm2), plus common spelled aliases. Unknown names return invalid_input.

Read the full KIT documentation →

Run — free

Worked example

Supported units and exact conversion factors

Common surface charge tasks

What you can do with it

ESD and corona-treatment labs

Textbook and homework electrostatics

FAQ

Related tools

For developers — API access

API endpoint

Call it from your stack

Example request

Example response

Pricing

Errors

Technical notes

Supported units and exact conversion factors

Request shape, response fields, and unknown-unit errors

Browser use, API pricing, and everyday workflows

Integration use cases

Materials and semiconductor pipelines

Technical questions

thank you