If you are gearing up to pop the big question and ask your love to be your lifetime partner, you probably already know how important a ring is to the process. For many, the most difficult part isn't choosing the stone or setting, it is making sure the ring is the right size to fit her finger. There are several ways to find out her ring size without spoiling the surprise. If you don't know your beloved's ring size and have your heart set on keeping your proposal plans a secret, try these tips for determining her ring size.

Ask Friends or Family

If your intended has a close friend, she is likely to know your love's ring size. Likewise, her mother or sister are likely to be privy to this info, too. However, you will need to exercise caution if you choose to ask family and friends for her ring size. Close friends may be tempted to share the juicy news with her, and she may feel slighted if her sister or mom knows you are planning to propose, and she doesn't. Carefully assess the relationships and the willingness of the others to keep your secret before you make the decision to let others in on the surprise while leaving her in the dark.

Play Detective

If you'd rather keep the upcoming engagement a secret from family and friends, too, and you don't want to risk the word getting out, there are other ways to find her ring size. If she commonly wears other rings, you may be in luck. You can either borrow one from her jewelry box and take it to the jeweler to be sized or make a tracing of the ring and compare it to a ring-sizing chart. Taking the ring to the jeweler will give you a more accurate size, but tracing the ring can work, too. Make the sure the ring you choose is worn on a similar size finger, preferably her ring finger. But beware: the ring finger on her dominant hand may be slightly larger than her non-dominant ring finger. If she is a lefty, that means a ring that fits her right hand may fit snugly on her left.

Try a Little Trickery

If you are close to your mother or sister, ask your girlfriend to help you pick out an inexpensive ring for your mother or sister. Ask your girlfriend to try the ring on so you can see what it will look like, and note the size she chooses. This will work well if you commonly buy jewelry for others, but don't try this if you've never purchased jewelry before, as it will tip her off to your plans. Other options include getting a buddy or one of your brothers to ask her to help pick out a ring for their girlfriend or daughter. The key to success with this method is making the purchase believable.

Use a Temporary Setting

Many fine jewelers provide temporary settings for engagement rings. These comfort rings contain the stone that you choose but are not in the final setting. Once you propose, and your loved one agrees to say "I do," you can return the temporary ring and have the stone set in the setting you prefer. This is a great option if you can't determine her size. It also lets her become part of choosing the final setting for the stone. 

Fess Up

Keeping your engagement plans a secret until you propose may seem like a lot of fun, but some women prefer to pick out their own engagement rings. If you suspect that your intended would prefer to be part of the process or may want to consider engagement and wedding sets, by all means be upfront about your plans. You can still choose the time and place for the actual engagement and rest assured not only that will the ring fit but also that it will be one she will treasure for a lifetime.

Start visiting companies like Emerson & Farrar to find rings that are to your and your love's taste.