| Scenario | Machine | Rate & duration | Add-ons | Typical total due* |
|---|---|---|---|---|
| Basic grind | 24-inch | Daily × 1 | Tooling, extractor | $310–$420 |
| Large slab prep | 40-inch | Weekly × 1 | Tooling, extractor, delivery | $2,050–$2,650 |
| Overtime shift | 30-inch | Daily × 3 | Tooling, overtime, waiver | $1,050–$1,450 |
1) Base rental
Base Rental = Base Rate × Duration Units × Quantity
2) Add-ons
Add-ons Total = Σ( Add-on Rate × Duration Units × Quantity )
3) Surcharges
Surcharges = Overtime + Weekend % × Base Rental + Fuel % × (Base Rental + Add-ons) + Late Fee
4) Protection
Damage Waiver = Waiver % × Subtotal
Insurance = Insurance % × Subtotal
5) Discounts and tax
Taxable = (Subtotal + Protection) − Discount
Tax = Tax Rate % × Taxable
Total Due = Taxable + Tax
- Pick the machine size that matches your area and access.
- Choose a rate type and enter duration units.
- Turn on add-ons like tooling and dust extraction.
- Add logistics fees such as delivery and pickup.
- Set surcharges and protection to match rental terms.
- Apply discounts and tax, then calculate totals.
- Export as CSV or PDF for approvals.
1) What this estimate is designed to capture
Rental invoices usually include more than the machine rate. This calculator itemizes the base period charge, common add-ons (tooling and dust control), fixed logistics fees, optional labor, surcharges, protection plans, discounts, and tax. That structure mirrors how most rental quotes are built for commercial floor prep work.
2) Machine size and why it changes the budget
Smaller grinders (around 18–24 inch) fit tight rooms and residential projects, while 30–40 inch units increase coverage on open slabs. Higher-width machines typically cost more per day, but can reduce rental days by finishing the same square footage faster, especially on large warehouses or retail floors.
3) Productivity basics (sq ft per hour)
Grinding speed depends on surface hardness, coating thickness, and desired profile. A common planning range is roughly 250–600 sq ft per hour for general prep, with slower rates for heavy removal. Use the area and productivity fields to estimate total hours, then convert hours into days based on your shift length.
4) Tooling is often the real variable
Diamond tooling can be billed as a daily add-on, by wear, or by grit set. Coarse steps for coating removal generally wear faster than polishing steps. Budget a separate tooling line item so you can swap rates per rental terms, surface condition, and the number of tooling changes expected.
5) Dust extraction and compliance costs
On many sites, dust control is not optional. A compatible dust extractor and filters help manage cleanup time and improve visibility and safety. Rental suppliers may price the extractor per day or week, and filter/collection bags may appear as consumables. Treat those as recurring costs across the full duration.
6) Delivery, pickup, and return timing
Logistics fees can rival a day of rental in some regions. Delivery/pickup charges are often fixed, while late return fees are usually triggered by missed cut-off times. If your schedule is uncertain, consider adding a buffer day or a late fee placeholder to avoid underestimating total due.
7) Overtime and shift planning
Many daily rates assume a standard shift (often near 8 hours). If crews run extended hours, suppliers may charge overtime per hour beyond the included limit. The overtime inputs let you model that risk for night shifts, accelerated timelines, or multi-crew operations.
8) Waivers, insurance, deposits, and cash flow
Damage waivers and insurance are frequently calculated as a percentage of the rental subtotal. Deposits are typically refundable holds, not a “cost,” but they matter for cash flow and approvals. This calculator shows deposit separately and includes an itemized breakdown for internal review.
1) Should I choose daily or weekly rental?
If you need the grinder for several consecutive days, weekly pricing often lowers the effective daily rate. Compare totals using both options, and include delivery, add-ons, and surcharges so you are not comparing rate-only numbers.
2) How do I estimate hours from square footage?
Divide area by productivity. For example, 1,200 sq ft ÷ 350 sq ft/hour ≈ 3.43 hours. Then divide by your shift length to estimate days. Adjust productivity downward for heavy coating removal or hard concrete.
3) Why include a dust extractor as a separate line?
Extractors are commonly priced separately and may require consumables like bags and filters. Separating the line item makes quotes easier to compare and helps you match site safety requirements without inflating the base rental rate.
4) What does “damage waiver” usually cover?
It commonly limits your liability for accidental damage, but it may exclude theft, misuse, or normal wear items. Use the waiver percent to model the fee, then confirm coverage details and exclusions with your supplier.
5) Is the security deposit part of the project cost?
Deposits are typically refundable, so they are not a final expense. However, they affect cash flow and may be required at pickup or delivery. This tool shows deposit separately and also displays a grand total including it.
6) How should I handle consumables and wear items?
Some suppliers bill consumables as a per-day add-on, while others charge based on actual usage. If you do not have exact terms, include a conservative daily consumables rate and revise it once you receive a written quote.
7) Can I export results for approvals or clients?
Yes. After calculating, use the Download CSV or Download PDF buttons at the top of the results card. The export includes an itemized breakdown and totals, which is useful for purchase orders and internal sign-off.