Measure your own place in a few minutes and get an honest starting range. Send it to a painter and they can prepare accurately before they visit — which is usually the difference between a guess over the phone and a price that holds.
Most painting quotes start with a walk-around and a number in someone's head. A painter who has already seen the areas, the condition and the access can price the actual work instead of pricing the uncertainty — and uncertainty is expensive.
It also means the quotes you collect are comparing the same job. Two painters given the same measured scope are answering the same question, which is not true of two site visits a week apart.
No. It is free and there is no account to create. You do need to keep the page open on the same device, because that is how your job is remembered.
It is a starting range, not a quote. It is built from the areas you measure and typical production rates for that kind of work, so it is far closer than a price per square metre — but only a painter standing in the building can commit to a figure.
No. Do the areas you want painted and skip the rest. A partial walkthrough is still far more use to a painter than a phone call.
What you measured, any photos you added, and your notes. Nothing else, and only the painter you choose to send it to.