Grams of product from moles calculator
Two moles of water at 18.015 g/mol make 36.03 grams of product. Enter the moles from your mole-ratio step and the product's molar mass to get the mass in grams for a yield table or a balance reading. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Moles
- 2
- Molar mass
- 18.015
- Grams
- 36.03 g
- Precision
- 10
This grams of product from moles calculator converts an amount of product in moles into a weighable mass in grams using the product molar mass. You supply the product moles n and the product molar mass in grams per mole; the engine multiplies them with the closed form grams equals moles times molar mass. Classic stoichiometry checks include two moles of water with a molar mass of eighteen point zero one five grams per mole, which yields thirty-six point zero three grams, and half a mole of sodium chloride with a molar mass of fifty-eight point four four grams per mole, which yields twenty-nine point two two grams. Zero product moles with any positive molar mass correctly returns zero grams. Zero or negative molar mass is rejected because mass cannot be recovered from moles without a positive conversion factor. Everything runs with finite deterministic arithmetic only: no network calls, no random sampling, and no date-dependent behaviour.
What product mass from moles means and what you get
In stoichiometry, theoretical or measured product is often known first in moles after applying mole ratios from a balanced equation. Lab work and lab reports then need that amount as a mass so a balance reading or a yield in grams can be compared. The link is molar mass: multiply the amount of product in moles by the product molar mass in grams per mole to obtain the product mass in grams.
There is no approximate solver, no periodic-table lookup, and no reaction balancer: you must supply both the product mole count and the molar mass yourself from a prior calculation, SDS, or bottle label.
Where product grams from moles fits in study, lab work, and software
Students meet this conversion after they finish a limiting-reactant mole analysis and must report theoretical yield in grams, when a homework set already states product moles and asks for mass, or when a contest problem expects a clear gram answer from a given mole amount and molecular weight. Teachers can pre-generate answer keys for common products such as water, carbon dioxide, and simple salts without trusting opaque calculator apps that switch units mid-step or round inconsistently.
Lab technicians and preparers use the same closed form when a protocol already measured or computed moles of product and only the molar mass remains: multiply and record the expected mass for yield tables and notebook entries. Developers call the same contract from scripts to seed deterministic test vectors for chemistry tutors, to normalize user-entered product moles before a lab notebook export, or to satisfy programming-challenge statements that demand grams rather than a hand-waved scientific-notation guess.
What you can do with it
Homework and theoretical yield mass
Convert known product moles and molar mass into grams for theoretical yield checks before percent-yield work.
Lab notebooks and education software
Turn computed product moles into weighable grams for lab reports, tutoring UIs, and automated worksheet generators.
FAQ
What does the grams of product from moles calculator cost?
It is free in your browser on this page.
How is product mass in grams computed?
The result is the product mass in grams.
What happens if molar mass is zero or negative?
A zero or negative molar mass cannot convert product moles into grams.
Does this tool find theoretical product moles from a limiting reactant?
No. It only multiplies known product moles by molar mass. Use a theoretical product-moles tool if you still need the mole ratio step.
Why are results rounded to a precision?
Default precision is 10 decimal places; you can set precision from 0 to 15.
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
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/chem/grams-of-product-from-moles \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"moles":2,"molar_mass":18.015}'const res = await fetch("https://api.kit.forhosting.com/chem/grams-of-product-from-moles", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"moles": 2,
"molar_mass": 18.015
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/chem/grams-of-product-from-moles",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"moles": 2,
"molar_mass": 18.015
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/chem/grams-of-product-from-moles", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"moles":2,"molar_mass":18.015}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"moles":2,"molar_mass":18.015}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/chem/grams-of-product-from-moles", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"moles": 2,
"molar_mass": 18.015
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "chem.grams_of_product_from_moles",
"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
Published price — no tokens, no invented credits. A failed task is never charged.
Limits
max_abs_value | 1000000000000000 |
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
What product mass from moles means and what the response contains
This calculator returns the normalized moles and molar_mass you provided, the computed grams of product, the precision used for display, a method tag grams_of_product_from_moles, a short formula string, and the mass unit g. Invalid inputs fail with invalid_input rather than inventing a mass. Rejected cases include missing moles or molar_mass, non-finite values, magnitudes above the documented ceiling, negative moles, and any zero or negative molar mass, because a non-positive molar mass cannot convert moles into grams.
How moles and molar mass are read and how grams stay reproducible
Optional leading plus signs and scientific notation on numeric strings are allowed when they parse as finite decimals; embedded spaces, hex prefixes, and non-numeric tokens are rejected with a clear message. Zero moles is valid and simply yields zero grams when the molar mass is positive, which is useful for empty-product edge cases and blank answer keys. The preferred field for the amount of product is moles, but aliases n, product_moles, moles_product, amount, and n_product are accepted so spreadsheets, query strings, and typed forms can reuse the same contract without renaming columns. The product molar mass uses molar_mass with aliases MM, mm, molecular_weight, mw, molarMass, and product_molar_mass; it must be a finite positive number in grams per mole. A zero or negative molar_mass fails with invalid_input and a message that names the field so a bad cell does not become a silent wrong mass. An optional precision field, with aliases decimals and dp, chooses how many decimal places to expose for the numeric outputs, defaulting to ten and capped at fifteen so JSON goldens stay stable across runs. Pair the free browser run on this page with the priced API when you need the identical mathematical result inside an automated pipeline without re-implementing the multiplication yourself.
Where product grams from moles fits in study, lab work, and software
Product and education tools use the endpoint when a learner types product moles and molar mass and the UI must show grams with a clear formula reminder. On this page the work runs entirely in your browser; through the API each successful lookup costs $0.002, failed validation is not charged, and nothing is stored after the response returns. That split — free interactive exploration and a priced, identical API — matches the rest of the KIT tier-A catalog and lets you move from a classroom demo to an automated pipeline without changing the mathematical result. Pair it with theoretical product-mole or mass-to-mass tools when you need related stoichiometry steps, and with other chem endpoints when you are building a small lab of free, deterministic helpers.
Integration use cases
Deterministic test fixtures
Generate reproducible product mass values for unit tests, chemistry tutors, and CI assertions on stoichiometry engines.