Titration equivalence point volume calculator
Titrating 25 mL of a 0.1 M sample with 0.1 M titrant reaches equivalence at 25 mL. Enter the analyte concentration and volume and the titrant concentration, plus mole coefficients when the reaction is not one-to-one, and size your burette before you start. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Analyte concentration
- 0.1
- Analyte volume
- 25
- Titrant concentration
- 0.1
- Analyte moles
- 1
- Titrant moles
- 1
- Equivalence volume
- 25
- Moles analyte
- 2.5
In a classical titration the equivalence point is the titrant volume at which the amount of titrant added exactly matches the analyte according to the balanced reaction stoichiometry. Students, lab technicians, and automated LIMS workflows need that volume quickly from three numbers: analyte concentration, analyte volume, and titrant concentration, optionally scaled by mole coefficients when the reaction is not one-to-one.
What equivalence volume means and which inputs to send
At the equivalence point the stoichiometric amounts of analyte and titrant are equal. With analyte concentration Ca, analyte volume Va, titrant concentration Ct, and optional positive mole coefficients na and nt for the balanced equation, the balance is na times Ca times Va equals nt times Ct times Veq. Solving for the unknown titrant volume gives Veq equals na times Ca times Va divided by nt times Ct.
When you omit the mole fields the calculator defaults both coefficients to one, which covers common monoprotic acid–base and many one-to-one redox pairs. Concentrations and volumes may use any consistent unit system: molarity with milliliters yields milliliters of titrant, while moles per liter with liters yields liters. Non-negative analyte values are allowed so blank samples and zero-analyte edge cases return a zero equivalence volume without crashing.
Titrant concentration must be strictly positive because a zero stock makes the required volume undefined.
Lab workflows and practical limits
Source inputs follow the same retention rules as other KIT parse items, and results are safe to pin because the algorithm is fully deterministic. Remember that this calculator reports the theoretical equivalence volume from mole balance only: it does not model indicator end-point lag, temperature effects, or activity corrections, so industrial release methods may still apply a laboratory-specific bias factor after you obtain Veq.
Keep units consistent across the three primary fields, keep titrant concentration away from zero, and treat extremely large inputs as a sign that unit conversion is needed rather than that the formula failed.
What you can do with it
Homework and exam verification
Students enter Ca, Va, and Ct for monoprotic titrations, confirm Veq against worked solutions, and receive a clear error when titrant concentration is zero by mistake.
Pre-lab burette planning
Technicians size the expected titrant volume before loading the burette, including diprotic cases via optional mole coefficients, without opening a spreadsheet.
FAQ
Is the titration equivalence point volume calculator free?
The browser tool runs free on your device.
Which units should I use?
Any consistent pair: mol/L with mL yields mL of titrant; mol/L with L yields L. The calculator does not convert units for you—keep Ca, Va, and Ct coherent.
How do I calculate the equivalence point volume?
Multiply the analyte concentration by the analyte volume and divide by the titrant concentration, scaling by the mole coefficients if they differ. A 25 mL sample at 0.1 M with 0.1 M titrant needs 25 mL.
How do I set up a diprotic acid?
Enter the mole coefficients from your balanced equation, for example one for the analyte and two for the titrant. Both conventions work as long as the ratio between them matches the reaction; left empty, both default to one.
Does the result include indicator end-point lag?
No. It is the theoretical volume from the mole balance alone, without indicator lag, temperature effects or activity corrections. Industrial methods may still apply their own laboratory correction after you obtain it.
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/titration-equivalence-volume \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"analyte_concentration":0.1,"analyte_volume":25,"titrant_concentration":0.1}'const res = await fetch("https://api.kit.forhosting.com/chem/titration-equivalence-volume", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"analyte_concentration": 0.1,
"analyte_volume": 25,
"titrant_concentration": 0.1
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/chem/titration-equivalence-volume",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"analyte_concentration": 0.1,
"analyte_volume": 25,
"titrant_concentration": 0.1
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/chem/titration-equivalence-volume", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"analyte_concentration":0.1,"analyte_volume":25,"titrant_concentration":0.1}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"analyte_concentration":0.1,"analyte_volume":25,"titrant_concentration":0.1}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/chem/titration-equivalence-volume", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"analyte_concentration": 0.1,
"analyte_volume": 25,
"titrant_concentration": 0.1
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "chem.titration_equivalence_volume",
"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.
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 solves the mole-balance equation deterministically, returns a structured JSON payload with the equivalence volume and intermediate mole products, and rejects a zero titrant concentration with a clear invalid input error so pipelines never divide by zero.
What equivalence volume means and which inputs to send
Send required fields analyte_concentration, analyte_volume, and titrant_concentration as finite JSON numbers or numeric strings; aliases such as ca, va, and ct are accepted when documented. Negative concentrations or volumes and non-positive mole coefficients fail with invalid_input and are not charged. Identical inputs always produce identical JSON because the path is pure arithmetic with no network, no random seed, and no wall clock.
Reading the response fields and choosing stoichiometry
Use the free in-browser titration equivalence point volume calculator for homework checks, pre-lab planning, and quick mental-math verification without spreadsheets. On success the response echoes the three required inputs, the effective analyte_moles and titrant_moles used, and the primary result equivalence_volume. The equation label is always the unicode mole-balance form and method is always titration_equivalence_volume so downstream code can branch without sniffing shapes. For a diprotic acid titrated with monobasic strong base set analyte_moles to one and titrant_moles to two, or the reverse depending on how you write the balanced equation; both conventions work as long as the ratio na over nt is correct. Use the prepaid API when a learning-management system, electronic lab notebook, or quality-control script needs a stable contract under KIT balance at $0.002 per successful item. Validation failures never consume balance after the engine rejects the request. Pair this endpoint with dilution or molarity converters when stock solutions must be prepared first, then feed the resulting concentrations here to size the burette fill.
API usage, pricing, lab workflows, and practical limits
Send a JSON body with the required finite numbers for analyte concentration, analyte volume, and titrant concentration, plus optional positive analyte_moles and titrant_moles when the stoichiometry is not one-to-one. Authors shipping teaching apps can map equivalence_volume directly into a burette gauge and show moles_analyte beside the balanced equation so learners connect the algebra to the glassware on the bench.
Integration use cases
LIMS and teaching-platform automation
Scripts and LMS tools call a stable prepaid endpoint to compute theoretical equivalence volumes for worksheets, auto-graders, and method templates.
Technical questions
How do I calculate equivalence point volume?
Send analyte_concentration, analyte_volume, and titrant_concentration. The response field equivalence_volume is Veq = (na·Ca·Va)/(nt·Ct) with na and nt defaulting to 1.
What happens if titrant concentration is zero?
The request fails with invalid_input. A zero titrant concentration would require division by zero, so the engine rejects it and does not charge the call.
Can I handle non-1:1 stoichiometry?
Yes. Optional analyte_moles and titrant_moles (aliases na, nt) scale the mole balance for reactions such as H2SO4 with two equivalents of NaOH.