Free field service tools for contractors and service businesses
11 trade-specific estimate builders and 2 business calculators — field service templates you can start from today, not finished software. No sign-up, no email, no credit card. Each one below says what it needs from you, what it gives back, and — importantly — what the result does not prove. Reviewed 1 August 2026.
Choose a tool by task
Pick the row that matches what you actually came here to do.
| If you need to… | Use | You will need |
|---|---|---|
| Put a professional-looking quote in front of a customer | The estimate builder for your trade | Your own prices and the scope of the job |
| Offer a customer options rather than one price | Any estimate builder — they support tiers | Three versions of the work, and a price for each |
| Work out where money may be leaking | Revenue leak calculator | Job volume, average ticket, and honest estimates of what slips |
| Understand tiered estimating before you try it | Tiered estimates for HVAC revenue | Ten minutes |
| Keep the estimate, the job and the invoice connected | The Opsler product, not a tool | A 14-day trial or the free plan |
Estimate builders by trade
These free estimate builders are each structured around the work of one trade: the line items that trade actually quotes, in the language it uses. You supply the prices.
Inputs: your services and your prices · Output: a structured estimate you can present or print · Reviewed: 1 August 2026
Business calculators and guides
These contractor calculators model a situation from numbers you provide. Read the last column before you act on any of them.
Revenue leak calculator
- Task:
- Model where money may be leaking out of your operation
- Inputs:
- Your job volume, average ticket, and your own estimates of missed follow-ups and uninvoiced work
- Output:
- A modelled annual figure based entirely on the numbers you enter
- What it does not prove:
- Nothing on its own. It is an arithmetic model of your assumptions, not a measurement of your business. Useful for deciding what to go and check in your accounts.
Tiered estimates for HVAC revenue
- Task:
- Understand how Good/Better/Best estimating changes a quote
- Inputs:
- Reading, plus your own pricing if you want to work through an example
- Output:
- An explanation of the tiered approach and how approval works
- What it does not prove:
- It describes a method. Whether it changes your average ticket depends on your work, your prices and your technicians — measure your own before and after.
How these tools handle your data
These tools run in your browser. There is no account, so there is nothing to log into and nothing stored against you. The numbers you type produce the result on screen; if you download or print it, the file is yours.
What that means practically: nothing is saved for you. Close the tab and the estimate is gone. That is the honest trade for a tool with no sign-up, and it is the main reason people eventually want a connected system instead.
Do not use a free tool as your record of what you quoted. If a customer disputes a price in three months, a browser tab you closed is not evidence. Keep your own copy of anything that matters.
From a one-off tool to a connected workflow
A free builder is the right answer when quoting is occasional and nothing needs to connect to anything. Plenty of one-person businesses run that way for years and are right to.
The signal that you have outgrown it is re-typing. The same customer entered into a builder, then a calendar, then an invoice. When that is happening several times a week, the cost is no longer the software — it is the twenty minutes a day and the charges that get missed in the copying.
In Opsler the estimate belongs to a job, the job to a customer, and the invoice comes from the job with the line items already on it. It is $25 per seat per month, with a free plan for two seats if you want to try the connected version without spending anything.
Field service tool questions
Yes and no respectively. Every tool on this page runs in your browser without a sign-up, an email address or a credit card. There is no trial clock and no gated result at the end. We build them because a contractor who gets something useful from us is more likely to look at the product later, and that only works if the tool is genuinely useful on its own.
The estimate builders and calculators run in your browser. The figures you enter are used to produce the result on screen and are not saved to an Opsler account, because there is no account involved. If you download or print a result, that file is yours and lives on your device. Do not treat any of these tools as a record-keeping system — they produce a document or a number for you to use, not a stored history.
No, and this is the most important caveat on the page. The builders give you structure — line items, tiers, a professional layout — not market rates. Labour rates, material costs and what a market will bear vary enormously between regions and between businesses, and no calculator on the internet knows your costs. Use your own prices. A tool that hands you a number and calls it the going rate is doing you a disservice.
A tool does one task once and forgets it. The product connects the tasks: the estimate you build becomes a job, the job becomes an invoice, the customer keeps a history, and next year you can see what you did for them. If you are building the occasional quote, a free builder is genuinely all you need. The moment you are re-typing the same customer's details into a second place, that is the point the connected version starts paying for itself.
Each card shows when it was last reviewed, and the whole hub was checked on 1 August 2026. If a tool stops working or produces something that looks wrong, tell us — a broken free tool is worse than no free tool, because someone acted on it. We would rather remove one than leave it misleading people.
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