Live in beta · 105 tools
105 calculators and free EICR, EIC and MEIWC certificate templates for marine and industrial electrical engineers. Every answer shows its working and names the standard it came from.
Tools
105
Across 16 categories, from cable sizing to CCTV pixel density.
Certificate templates
EIC, EICR, MEIWC, IR test, PAT and more.
Standard
Removes Jolt branding and saves your work. Everything else is free.
On site
Runs in a switchroom, an engine room or a hold. No signal needed.
Every tool names the standard it works to and shows the intermediate steps — derating factors, corrections, limits — so you can defend the number in a review. All of it is free to use and free to download.
Cable sizing, fault levels, volt drop and battery banks, with every derating factor shown rather than folded into the answer.
Templates that fill themselves from the calculation you just ran. Download the PDF free with Jolt branding, or put your own logo on it.
Site paperwork filed against the job rather than scattered across your camera roll and three group chats.
Eight certificate templates to BS 7671:2018+A4, free to fill in and free to download as PDF. No card, no trial, no watermark across the page — completed certificates carry a small Jolt mark in the footer, and £6.99 a month replaces that with your own logo.
EICR
Sections A–L of the BS 7671 model form, with the schedule of inspection and the generic schedule of circuit details.
Free to download · BS 7671:2018+A4
EIC
For new installations, additions and alterations, with the design, construction and inspection declarations.
Free to download · BS 7671:2018+A4
MEIWC
For work that does not extend to a new circuit — the short form, with test results.
Free to download · BS 7671:2018+A4
IR
Circuit-by-circuit insulation resistance, recorded in MΩ against the minimum permitted.
Free to download · BS 7671 Part 6
SOI
The tick-list of inspected items that accompanies an EIC or EICR.
Free to download · BS 7671:2018+A4
SOR
R₁+R₂, Zs, insulation resistance, polarity and RCD operating times per circuit.
Free to download · BS 7671:2018+A4
PAT
Asset register with class, test result, next-test date and inspector.
Free to download · IET Code of Practice
EX
Hazardous-area equipment inspection, grade and schedule, with the checklist behind it.
Free to download · IEC 60079-17
Open a free EICR template Fills itself from the calculation you just ran, and works offline on site.
If yours isn't here, the contact form goes to a working electrical engineer, not a ticket queue.
Everything you need to do the job. All 105 calculators, every certificate template including EIC, EICR and EX inspection, the reference tables, and the full working behind each result. You can download any completed certificate as a PDF at no cost — it carries a small Jolt mark in the footer. No card, no expiry, no trial clock.
Yes. You can fill in a complete Electrical Installation Condition Report — all twelve sections of the BS 7671 model form, the schedule of inspection and the schedule of test results — and download it as a PDF without paying anything or entering a card. The free version carries a small Jolt mark in the footer. The £6.99 subscription replaces that mark with your own logo and company details, and keeps your reports saved between sessions. The same applies to the EIC, MEIWC, PAT and EX inspection templates.
IEC 60092-352 for marine cable sizing, IEC 60909 for fault levels, IEEE 485 for battery sizing, BS 7671:2018+A4 for inspection and testing, plus SOLAS and HSE guidance where they apply. Every result names the clause or table it came from, so you can check it against the book.
Jolt shows its working — the derating factors, the corrections, the limit it checked against — rather than handing you a figure and asking you to believe it. That is what lets you defend the result in a review. It does not make the decision for you: you remain the responsible engineer, and anything that matters should be checked the way you would check any calculation.
Yes. Install it to your home screen and it runs in a switchroom, an engine room or a hold with no connection. Work saves to the device and syncs when you are back in range.
Add your logo and company details once in your profile and they appear on every PDF and certificate you export, with a signature block for sign-off.
Two things. Your own logo and company details replace the Jolt mark on every PDF and certificate, so the paperwork goes out as yours. And your work saves — projects, field records, photos and calculation history, on the device and synced — instead of living only in the session you are in. Cancel any time from the billing portal; access runs to the end of the period you have paid for.
Everything you need to do the job
No card, no trial clock
Your name on it, and your work kept
Billed monthly · cancel anytime
Prices in GBP, VAT where applicable. Cancel anytime — access runs to the end of the period you have paid for, and everything you made stays downloadable on the free plan. Teams and multi-seat licences, get in touch.
Jolt was born out of frustration. As a working electrical engineer I kept reaching for the same calculations, certificates and references every day — scattered across spreadsheets, PDFs and memory.
So I built one fast, professional app bringing together 105 calculators and certificate templates aligned to the standards engineers actually work to. Designed for the real world — on vessels, in switchrooms, on site — where accuracy matters and time is short.
Jakub Burakowski — Founder and Electrical Engineer, Glasgow
Questions, bug reports, team licences — you will get a reply from a real engineer.
Jolt is operated from Glasgow, United Kingdom. For any privacy question, use the contact form.
If you contact us: your name, email and message. If you create an account: the details needed to run it — email, authentication data, and any company details you add for report branding.
To reply to you, to provide and secure the app, and to process payments. We do not sell your data or use it for third-party advertising.
Resend for transactional email, Clerk for authentication, Supabase for storage, Stripe for payments — each under its own privacy policy. See resend.com/privacy.
Contact messages are kept while needed to handle your enquiry. Account data is kept while your account is open and deleted on request.
This site uses no tracking cookies. The app uses cookies strictly necessary for sign-in; Stripe sets cookies necessary for payment at checkout.
You can request access to, correction of, or deletion of your personal data at any time via the contact form. You can also complain to the UK Information Commissioner's Office (ico.org.uk) if you're unhappy with how we've handled your data.
Some processors above may handle data outside the UK — Stripe and Clerk both operate internationally. Where that happens, it's done under standard contractual clauses or an equivalent safeguard recognised under UK GDPR.
Jolt is a professional tool for electrical engineers and isn't directed at, or intended for use by, anyone under 18.
These terms cover your use of Jolt (joltit.app and dash.joltit.app), operated from Glasgow, United Kingdom. By creating an account or using the app you agree to them. If you don't agree, please don't use Jolt.
Jolt is a suite of electrical engineering calculators, reference material and certificate templates, offered on a free plan and a paid Standard plan. Features and tools may be added, changed or retired over time.
You're responsible for the accuracy of the information you give us and for keeping your sign-in credentials secure. Let us know straight away if you think your account has been accessed without your permission.
Paid plans are billed via Stripe in GBP, plus VAT where applicable. You can cancel at any time — access continues to the end of the period you've already paid for, and anything you made stays downloadable on the free plan afterwards. We don't offer partial refunds for unused time.
Don't use Jolt for anything unlawful, don't try to reverse engineer or resell the app, and don't attempt to disrupt or gain unauthorised access to it or to other users' data.
Jolt's calculators, templates and reference content are tools to assist a competent electrical engineer — they are not a substitute for professional judgement, site verification or the sign-off of a suitably qualified person. You remain responsible for checking and standing behind any calculation, certificate or report before it's relied on, especially for safety-critical installations.
Jolt and its content, design and code belong to us or our licensors. You keep ownership of the data, reports and documents you create using the app.
We work to keep Jolt available and reliable but don't guarantee uninterrupted access — the app may occasionally be unavailable for maintenance or reasons outside our control.
To the extent the law allows, we're not liable for indirect or consequential losses arising from your use of Jolt. Nothing here limits liability where the law doesn't allow it to be limited, such as for death, personal injury caused by negligence, or fraud.
You can close your account at any time. We may suspend or close an account that breaches these terms or the acceptable use section above.
We may update these terms as the app evolves. Continuing to use Jolt after a change means you accept the updated terms.
These terms are governed by the laws of Scotland, and any dispute will be handled by the Scottish courts.
joltit.app itself doesn't set any cookies and uses no analytics or advertising trackers.
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