Yes, a precise kitchen scale can weigh parcels for postage if it reads in ounces, handles tare, and you round the weight correctly.
You want to ship from home without buying a dedicated postal scale. The good news: many modern food scales are accurate enough for small parcels and padded envelopes. The trick is to work within carrier rules for rounding, weight tiers, and dimensional weight. This guide shows how to check your scale, weigh mail the right way, pick the right label, and avoid surprise postage due.
Using A Kitchen Scale For Postage—What Works And What Doesn’t
Digital cooking scales typically offer 0.1 oz or 1 g resolution with a capacity between 5 lb and 11 lb. That is fine for most e-commerce trinkets, crafts, and returns. A postage-only scale adds niceties like higher capacity, hold-to-lock readings, and label-printing links. If your mail is light and you follow carrier math, a kitchen unit is a practical stand-in.
Quick Comparison Of Scale Options
The table below helps you decide whether your current device is suitable, and when a shipping model pays off.
| Scale Type | Resolution & Capacity | Best Use |
|---|---|---|
| Digital Kitchen | 0.1 oz to 0.01 oz; 5–11 lb | Envelopes and small boxes; weighs in grams/ounces; use tare for mailers |
| Postal/Shipping | 0.1 oz or finer; 25–70 lb+ | Frequent shipping; bigger boxes; hold function avoids auto-off mid-weigh |
| Mechanical Spring | Coarser readouts; 5–25 lb | Not ideal for ounce-tiered postage; hard to read small changes |
Carrier Rules You Must Match With Any Scale
Two ideas decide the price you pay: rounding of weight and dimensional weight. Miss either and your label can be short paid.
Rounding: Ounces And Pounds
USPS rounds up weights. Ounce-priced parcels step up by ounce tiers. Pound-priced parcels round to the next pound. That means 15.2 oz pays the 16 oz tier, and 3 lb 1 oz pays the 4 lb rate. Enter the higher tier when you buy postage to stay compliant.
Dimensional Weight: When Size Sets The Bill
Carriers may price large, light boxes by a size-based formula instead of the scale reading. USPS applies dimensional weight above one cubic foot for many services. UPS and FedEx apply it on many services and may round each fractional inch up, which can raise billed size. If your box is big and light, run the dim calc before you print.
How To Weigh Mail Correctly On A Food Scale
Follow these steps to get a reliable reading and the right label.
1) Place And Zero
Put the scale on a stable, level surface. Tap tare to zero. If your parcel is floppy, place an empty bowl or box lid on the scale, tare again, then load the parcel so it sits flat.
2) Weigh Packed, Ready-To-Seal Items
Weigh after you add fillers, tape, and label. Extra tape, a bubble pouch, or a thicker mailer can tip a lightweight parcel over a tier.
3) Read In Ounces
Switch to ounces, not only grams. Postage tools accept decimals in ounces and expect you to match ounce tiers. Write the weight on the box so you enter the same number when buying the label.
4) Round The Way Carriers Do
For ounce-rated mail, round up to the next ounce tier. For pound-rated mail, round up to the next pound. A kitchen display that shows 0.2 oz swings will still work if you follow rounding.
5) Double-Check Big, Light Boxes
Measure length, width, and height to the nearest whole inch. If the cubic inches exceed one cubic foot, check dimensional weight and compare it to the scale reading. Pay the higher of the two.
When A Dedicated Postal Scale Makes Sense
Buy a shipping scale if you ship daily, send boxes over 10 lb, or need a hold button to freeze the reading when a carton hangs off the platform. USB/Bluetooth models talk to label software and skip manual entry. For occasional sellers and household returns, a precise kitchen unit does the job.
USPS Ounce Tiers And Where A Food Scale Fits
Ground Advantage handles most small parcels. Under one pound, the price steps at 4, 8, 12, and 15.999 oz. Above that, rates charge by the pound up to 70 lb. The matrix below shows how your reading maps to the label you buy.
| Actual Weight On Scale | USPS Rate Bucket | Notes |
|---|---|---|
| 0.1–4.0 oz | Up to 4 oz tier | Round up within the tier; tracking included |
| >4.0–8.0 oz | Up to 8 oz tier | Any decimal goes to the next ounce inside the tier |
| >8.0–12.0 oz | Up to 12 oz tier | Still ounce-priced; zone matters |
| >12.0–15.999 oz | Up to 15.999 oz tier | Just under a pound; if 16.0 oz or more, move to pounds |
| 1 lb 0.1 oz–1 lb 15.9 oz | 2 lb rate | Pound-priced, round up to next pound |
Accuracy Checks For A Kitchen Scale
You don’t need lab calibration for home shipping. You do need repeatable readings within a few tenths of an ounce. Run these quick checks once a month or before a heavy mailing day.
Repeatability
Weigh the same parcel three times. If your readings wander more than 0.2 oz, replace batteries, warm up the scale for a minute, and re-test.
Linear Check
Stack a couple of small objects and add them in steps. The difference between steps should match. If step gains are inconsistent, treat the device as suspect above one pound.
Tare Behavior
Place an empty mailer and tare. Add your item. Remove it. The display should return to zero. If it drifts, clear tare and restart the unit.
Common Mistakes That Trigger Postage Due
- Weighing a half-packed box, then adding tape and a label.
- Entering grams into a postage tool set to ounces.
- Ignoring dimensional weight on puffy apparel boxes.
- Letting auto-off cut power before the reading stabilizes.
- Rounding down to “save” a few cents. Carriers audit and bill the difference.
How To Measure For Dimensional Weight
Use a rigid ruler or tape. Measure length, width, and height at the longest points. Round each to a whole inch per carrier guidance. Multiply L×W×H to get cubic inches. For USPS, if that number is over 1,728, compare the resulting dimensional weight to the scale weight and pay the higher one. UPS and FedEx apply dim weight on most services and may round every fraction of an inch up, so precise measuring saves money.
Label Buying Tips That Pair Well With A Food Scale
Use Official Online Tools
Print labels through USPS Click-N-Ship or a trusted platform. Ounce-tier prompts reduce entry mistakes and show when you cross into a pound-based price. You can also schedule pickups from your doorstep—fast and simple.
Enter Ounces Exactly
Match your display readout to the nearest ounce tier. If your reading is 7.1 oz, buy the 8 oz tier. If your reading is 1 lb 0.2 oz, buy the 2 lb rate. That keeps you aligned with carrier math.
Mind Service Cutoffs
Sub-pound parcels fit the ounce tiers shown above. Heavier shipments move to pound-based rates where each extra ounce can push you into the next full pound.
When Your Scale Isn’t Enough
Upgrade if you ship guitars, bulk pantry refills, or anything that bends the platform. A larger top plate and a hold button prevent wobble and missed readings. If your unit only reads in grams, it can still work; convert to ounces inside your label tool and follow ounce or pound rounding rules.
Practical Workflow For Home Shippers
- Pack the item fully. Seal it.
- Weigh on a flat surface. Read ounces.
- Measure box size. Round each side to whole inches.
- Check for dim weight on large boxes.
- Buy the matching tier or pound rate. Print.
- Drop off or schedule pickup.
FAQ-Style Clarifications Without The Fluff
Do I Need Legal-For-Trade Certification?
No. You’re not selling by weight. You just need honest readings that match carrier rounding.
Will The Post Office Reweigh My Parcel?
Yes, parcels can be audited in transit or at acceptance. If the actual weight or dim weight is higher than the label, postage due may be billed to you or collected from the recipient.
What About Letters And Flats?
Letters and flats use their own size and ounce limits. If what you’re sending is stiff, lumpy, or thick, move to a parcel service and weigh it as a package.
Edge Cases And Pro Tips
Soft mailers with air inside can creep into dim rules once packed. Compress air with a second strip of tape, then re-measure. Tubes often read shorter on one axis and taller on another; measure true height across the cap. If your display flickers near a tier break, pick the higher tier. The cents you try to save can turn into a fee and a delay. When unsure, have one parcel weighed at the counter to validate your routine.
Bottom Line For Home Mailers
A well-behaved digital kitchen scale is fine for small parcels and padded mailers. Follow ounce and pound rounding, measure big boxes for dim weight, and buy labels using official tools. If your shipping grows, a postal scale adds speed and convenience, but accuracy—not the label on the device—sets your price.