TL;DR: LaChart is a lactate analysis tool that starts free, and for a lot of people free is enough. Its pricing follows a freemium model: the lactate curve calculator runs without an account, and a Free plan gives you your first three lactate tests with your curve and zones (LaChart pricing, free calculator). For more, LaChart lists two paid subscription plans: Athlete at 6.99 EUR per month with unlimited tests and a training calendar, and Coach at 14.99 EUR per month for unlimited athletes with branded PDF reports. Both start with two weeks free (LaChart pricing). Coachbox publishes its prices too: coaching plans from 19 EUR per month billed yearly (excl. VAT), with free lactate tests at the start of your license and 3 to 6 EUR per test after that (excl. VAT), or a standalone Lactate Module for labs and occasional testers. The two bill in different ways, and this page shows what each one costs and how.
LaChart Pricing: The Simple Answer
LaChart lists three plans on its pricing section (LaChart pricing):
| Plan | Price as LaChart lists it | What LaChart lists in the plan |
|---|---|---|
| Free | 0 EUR / month | 3 lactate tests, Garmin and Strava sync, lactate values on intervals, connect with your coach, basic analytics |
| Athlete | 6.99 EUR / month, 2 weeks free | Unlimited lactate tests, full test history, population comparison, PDF export of test reports, structured workouts pushed to Garmin, a weekly calendar, workouts from the app and a smart trainer, load and form over the full history, priority support |
| Coach | 14.99 EUR / month, 2 weeks free | Everything in Athlete, unlimited athletes, unlimited PDF reports, PDF branding with your logo, title and address, workouts planned for your athletes and pushed to their Garmin, a coach dashboard |
Source: LaChart pricing. LaChart does not say whether these prices include VAT, and we did not find a yearly billing option on the pricing section, so the table shows the amounts exactly as listed. LaChart says you can cancel anytime.
LaChart also states that the Coach plan does not charge per lactate test and does not rise with the number of athletes (LaChart’s Coachbox comparison).
What You Get Without Paying
Two things stay free. The lactate curve calculator draws your curve and reads LT1 and LT2 without an account, and shows fixed-point methods such as OBLA, IAT, D-max and log-log beside them. According to the same page, a free account adds the remaining methods, a confidence score and training zones built from the thresholds (free calculator). LaChart’s homepage describes it differently and says the calculator shows matching training zones without an account (LaChart). A free account then saves your first three tests with your curve and zones (LaChart pricing). The calculator page also carries a Buy Me a Coffee link for people who want to support the project (free calculator).
In our view, that is a generous way in. You can try several of LaChart’s threshold methods on your own data before you give anyone an email address.
The Real Cost of Free: What the Free Plan Leaves Out
The Free plan is a starting point, not the full product. Going by LaChart’s own plan list (LaChart pricing):
- Three tests. Unlimited lactate tests start on the Athlete plan (LaChart pricing).
- Test history. The full history behind your tests, to compare every curve, sits in the Athlete plan.
- Planning. The calendar that pushes structured workouts to your Garmin is part of Athlete and Coach.
- Coaching a roster. Unlimited athletes, workouts planned for your athletes and the coach dashboard are part of the Coach plan.
- Your name on the report. PDF branding with your logo, title and address is part of the Coach plan.
One detail to check yourself: LaChart’s FAQ says a free account adds saving, history, comparison and PDF export (LaChart FAQ), while its plan list puts full test history and PDF export under Athlete (LaChart pricing). Try the Free plan to see where the line sits today.
When Free Is Enough
In our view, LaChart’s Free plan and calculator cover these cases well:
For Students and Learners
If you study sport science and want to practice reading lactate curves, the calculator lets you do that without an account (free calculator). LaChart also publishes long-form guides on test protocols and threshold methods (LaChart lactate guide).
For Occasional Self-Testers
Athletes who test themselves a few times a year and want to see their curve and zones can start with three saved tests on the Free plan (LaChart pricing).
For Quick One-Off Analysis
Sometimes you just need to plot a curve. Someone shares test data and you want to see it on the spot. The no-registration calculator is built for that (free calculator).
When Free Isn’t Enough
Once you test more than three times, coach other people, or want reports with your name on them, you move to a paid plan, on LaChart or elsewhere (LaChart pricing). From that point the question is no longer free versus paid. It is which paid model fits the way you work, and that is where LaChart and Coachbox differ.
You Test Often
LaChart’s Athlete and Coach plans include unlimited lactate tests (LaChart pricing). Coachbox includes free tests at the start of your license and charges per test after that. If you run a high volume of tests, weigh that difference.
You Manage a Roster
LaChart’s Coach plan covers unlimited athletes at one listed price (LaChart pricing). Coachbox plans include a set number of athletes and charge per extra active athlete, meaning an athlete with workouts planned in the future.
You Want Testing and Coaching in One Place
Both products connect testing to training. LaChart builds zones from your test and pushes structured sessions to the athlete’s Garmin (for coaches, planning). Coachbox does the same, with zones from the Lactate Module flowing into the training plan, and sends structured workouts to Garmin, Coros and Wahoo.
How Coachbox Pricing Compares
Coachbox offers two paths for lactate testing, depending on whether you need the coaching platform or only the testing module (Coachbox pricing). All Coachbox prices below exclude VAT.
Option 1: Coaching Plans (for coaches who also test)
Lactate testing is part of every Coachbox coaching plan. Each plan includes free lactate tests at the start of your license, and after that you pay per test.
| Plan | Price excl. VAT | Athletes (extra fee excl. VAT) | Lactate tests (fee excl. VAT) |
|---|---|---|---|
| Base | 19 EUR/month billed yearly, or 25 EUR billed monthly | 5 included, 2.50 EUR per extra | 5 free at the start, then 6 EUR per test |
| Build | 49 EUR/month billed yearly, or 65 EUR billed monthly | 25 included, 2 EUR per extra | 10 free at the start, then 5 EUR per test |
| Peak | 79 EUR/month billed yearly, or 99 EUR billed monthly | 50 included, 1.75 EUR per extra | 15 free at the start, then 4 EUR per test |
| Prime | 149 EUR/month billed yearly, or 190 EUR billed monthly | 100 included, 1.50 EUR per extra | 20 free at the start, then 3 EUR per test |
The extra-athlete fee counts active athletes only, meaning athletes with workouts planned in the future. Every plan includes unlimited coaches and the full feature suite: training planning, a workout builder, annual planning, athlete communication and analytics. You get a 14-day free trial.
Option 2: Lactate Module Standalone (for labs and occasional testers)
For sports labs, physiologists and practitioners who do not need a coaching platform, there is a standalone Lactate Module at 49 EUR per month billed yearly, excl. VAT, plus one-time test bundles, also excl. VAT: 50 tests for 250 EUR, 100 tests for 400 EUR or 250 tests for 750 EUR (Coachbox pricing).
What You Get for the Money
| Feature | LaChart | Coachbox |
|---|---|---|
| Price for a coach | Coach plan: 14.99 EUR/month as listed, VAT basis not stated (pricing) | From 19 EUR/month billed yearly, excl. VAT |
| Athletes | Unlimited on the Coach plan (pricing) | 5 to 100 included, then 1.50 to 2.50 EUR per extra active athlete, excl. VAT |
| Lactate tests | 3 on Free, unlimited on Athlete and Coach (pricing) | 5 to 20 free at the start, then 3 to 6 EUR per test, excl. VAT |
| Threshold methods | LT1 and LT2 by six methods, including log-log, IAT, OBLA, D-max and LTP (lactate testing) | Automatic LT1 and LT2 in under a minute, with multiple methods |
| Entering a test | Type the stages as you run them (lactate testing) | Type the values, or read in a photo of a paper protocol |
| Spirometry data | We did not find it on LaChart’s lactate testing page (lactate testing) | Yes, spirometry data can be added to a lactate test |
| Zones | 5 zones or a Seiler 3-zone model, in power, pace and HR (LaChart) | Customizable zone models |
| Test history and comparison | Yes, curves overlaid across tests (lactate testing) | Yes |
| Branded PDF reports | Yes, on the Coach plan (pricing) | Yes, the lactate test PDF in your own brand, on every plan |
| Training calendar and workout builder | Yes (planning) | Yes |
| Season and race planning | An annual training plan with periodised blocks, target load, races and taper (for coaches) | Annual planning |
| Workouts sent to the watch | Garmin (integrations) | Garmin, Coros and Wahoo |
| Device sync | Strava, Garmin, Apple Health, plus FIT upload (integrations, LaChart) | Garmin, Polar, Suunto, Coros, Wahoo, Fitbit and Apple Watch |
| Athlete communication | Comments on each training (coaching) | In-app messaging and workout feedback |
| HRV, sleep and resting HR | Yes, via Apple Health, plus illness and injury episodes (health, integrations) | Yes, synced from the device, with injuries logged as milestones |
| Apps | Web platform, iPhone app and an Apple Watch face with your zones; Android announced as next (terms, integrations, LaChart) | Web, iOS and Android |
| AI assistant | We did not find one on LaChart’s feature pages (features) | Coachbox AI answers questions about your athletes and writes changes into the plan, plus an MCP connection to ChatGPT, Claude and other assistants |
A training calendar, a workout builder, annual planning, Garmin sync, test history, HRV and sleep tracking, comments on individual workouts and branded PDF reports are common ground: both products offer them, as LaChart’s feature pages and the sources in the table above show.
LaChart does not state on its pricing section whether its prices include VAT, so we show them as listed and do not convert them. Coachbox prices exclude VAT.
How Each One Bills: When Does Paying Make Sense?
The two products charge in different ways, so we do not add up a yearly total per roster. A single number would hide the conditions behind it.
LaChart charges one listed monthly price per coach: 14.99 EUR for the Coach plan, with unlimited athletes and unlimited lactate tests (LaChart pricing, LaChart’s Coachbox comparison). Your cost stays the same as your roster or your test volume grows. We did not find a plan for several coaches sharing one roster on its pricing section or its page for coaches (LaChart pricing, for coaches).
Coachbox charges a plan by roster size, billed yearly or monthly, with unlimited coaches included. Extra active athletes and lactate tests after the free ones add a published fee. Your cost grows with your roster and your test volume, and athletes without future workouts do not count.
On listed prices alone, LaChart’s Coach plan is below the lowest Coachbox plan, whatever its VAT basis turns out to be (LaChart pricing). Which one fits you depends on how many coaches work together, how many tests you run, and which features in the table above you need. In our view, a solo coach with a large roster who tests often gets a low, predictable bill from LaChart. A coaching team that wants several coaches on one account, spirometry data in its tests, apps on both platforms or an AI assistant should put those next to the price.
Who Should Use LaChart
Use LaChart if you want to try lactate analysis on your own data without an account, if you are a self-testing athlete who wants unlimited tests and a training calendar at a low monthly price, or if you are a solo coach who tests a lot and wants one price for unlimited athletes and tests (LaChart pricing). Testing studios that only run step tests and hand over a report will find a workflow built for them, with branded PDFs and no app for the client to install (for testers). In our view, LaChart is also a good fit if you like to compare several threshold methods on one curve and choose the one you can defend.
Look at Coachbox if several coaches work with the same athletes, if you want spirometry data in your lactate tests, if your athletes want Polar, Suunto or Coros workouts to sync on their own instead of by FIT upload, or a native Android app, if you send workouts to Coros or Wahoo, or if you want an AI assistant that works in the training plan. Labs that only test can compare LaChart with the standalone Coachbox Lactate Module.
The Bottom Line
LaChart’s free calculator and Free plan make it easy to start. For students, occasional self-testers and quick one-off curves, in our view free is enough.
Once you coach or test regularly, you are comparing two paid models. LaChart lists one monthly price per coach with unlimited athletes and tests. Coachbox lists plans by roster size with a per-test price after the free tests, and includes features we did not find on LaChart’s site, such as spirometry data, several coaches on one account and Coachbox AI. Start from how many athletes you coach, how often you test and which of those features you use, and the right choice follows from there.